Systems and methods for particle analysis

ABSTRACT

The present disclosure provides systems and methods for sorting a cell. The system may comprise a flow channel configured to transport a cell through the channel. The system may comprise an imaging device configured to capture an image of the cell from a plurality of different angles as the cell is transported through the flow channel. The system may comprise a processor configured to analyze the image using a deep learning algorithm to enable sorting of the cell.

CROSS-REFERENCE

This application claims the benefit of U.S. Patent Application No. 62/764,965, filed Aug. 15, 2018, which is entirely incorporated herein by reference.

BACKGROUND

Cell physical and morphological properties can be used to study cell type and cell state and to diagnose diseases. Cell shape is one of the markers of cell cycle. Eukaryotic cells show physical changes in shape which can be cell-cycle dependent, such as a yeast cell undergoing budding or fission. Shape is also an indicator of cell state and can become an indicator used for clinical diagnostics. Blood cell shape may change due to many clinical conditions, diseases, and medications, such as the changes in red cells' morphologies resulting from parasitic infections. Other parameters such as features of cell membrane, nuclear-to-cytoplasm ratio, nuclear envelope morphology, and chromatin structure can also be used to identify cell type and disease state. In blood, for instance, different cell types are distinguished by factors such as cell size, cell shape, and nuclear shape.

Biologists and cytopathologists use cell size and morphology to identify cell type and diagnose disease. This is mainly done by some sort of microscopic imaging and manual analysis of the images. As a result, the existing methods are time consuming, subjective, qualitative, and prone to error. Cytopathologists, for instance, review slides prepared from different tissues using a light microscope and look for features that resemble characteristics of disease. This process is time-consuming and the results are subjective and may be impacted by factors such as the orientation of the stained cells, how the slide was prepared, and the expertise of the cytopathologists. Although there have been recent efforts to automate the analysis of cytology smears, there are still challenges. One of the main problems with the analysis of the smears is the existence of contaminant cells that are hard to avoid and make it difficult to detect rare cells or specific feature characteristics of disease. Other issues are the angles of the stained or smeared cells, which can obscure essential information for identification of a cell type or state. As such, there remains a need for improved methods and/or systems for cell analysis.

SUMMARY

In an aspect, the present disclosure provides a cell sorting system comprising: a flow channel configured to transport a cell through the channel; an imaging device configured to capture an image of the cell from a plurality of different angles as the cell is transported through the flow channel; and a processor configured to analyze the image using a deep learning algorithm to enable sorting of the cell.

In some embodiments, a width or a height of the flow channel is non-uniform along an axis of the flow channel. In some embodiments, the width or the height of the flow channel gradually increases along a direction of the flow channel through which the cell is transported.

In some embodiments, the flow channel comprises walls that are formed to focus the cell into a streamline. In some embodiments, the system is configured to focus the cell into the streamline using inertial lift forces or hydrodynamic forces. In some embodiments, the system is further configured to focus the cell at a height within the flow channel. In some embodiments, the system is configured to rotate the cell within the streamline. In some embodiments, the flow channel comprises a square, rectangular, round, or half-ellipsoid cross-section.

In some embodiments, the plurality of angles extend around the cell or over a portion of the cell.

In some embodiments, the image comprises a plurality of images captured from the plurality of angles, wherein the plurality of images comprise: (1) an image captured from a top side of the cell, (2) an image captured from a bottom side of the cell, (3) an image captured from a front side of the cell, (4) an image captured from a rear side of the cell, (5) an image captured from a left side of the cell, or (6) an image captured from a right side of the cell.

In some embodiments, the image comprises a two-dimensional image or a three-dimensional image.

In some embodiments, the flow channel is configured to transport a plurality of cells through the flow channel, wherein the plurality of cells comprise the cell, and wherein the imaging device is configured to capture a plurality of images of the plurality of cells from a plurality of different angles relative to each of the plurality of cells.

In some embodiments, the imaging device is configured to capture the plurality of images onto a single image frame.

In some embodiments, the flow channel branches into a plurality of channels, and the system is configured to sort the cell by directing the cell to a selected channel of the plurality of channels based on the analyzed image.

In some embodiments, the system further comprises a laser-validation module configured to detect the cell after the cell has been sorted.

In another aspect, the present disclosure provides a method of sorting a cell, the method comprising: transporting a cell through a flow channel; capturing an image of the cell from a plurality of different angles as the cell is transported through the flow channel; and analyzing the image using a deep learning algorithm to sort the cell.

In some embodiments, the method further comprises rotating the cell as the cell is being transported through the flow channel. In some embodiments, the method further comprises focusing the cell into a streamline at a height within the flow channel as the cell is being transported through the flow channel.

In some embodiments, a plurality of images comprising the image are captured at a rate of about 10 frames per second to about 500,000 frames per second.

In some embodiments, the plurality of angles extend around the cell or over a portion of the cell.

In some embodiments, capturing the image of the cell comprises capturing a plurality of images from (1) a top side of the cell, (2) a bottom side of the cell, (3) a front side of the cell, (4) a rear side of the cell, (5) a left side of the cell, or (6) a right side of the cell.

In some embodiments, the method further comprises sorting the cell based on the analyzed image, by directing the cell to a selected channel of a plurality of channels downstream of the flow channel. In some embodiments, the plurality of channels excluding the selected channel are closed prior to directing the cell to the selected channel. In some embodiments, the plurality of channels excluding the selected channel are closed using pressure, an electric field, a magnetic field, or a combination thereof. In some embodiments, the method further comprises validating the sorting of the cell using a laser.

In some embodiments, the method further comprises sorting a plurality of cells at a rate of at least 10 cells per second, wherein the plurality of cells comprises the cell.

In some embodiments, the method further comprises: sorting a plurality of cells including the cell using a classifier; and feeding data from the sorting back to the classifier in order to train the classifier for future sorting. In some embodiments, the classifier comprises a neural network. In some embodiments, the classifier is configured to perform classification of each of the plurality of cells, based on classification probabilities corresponding to a plurality of analyzed images of the plurality of cells.

In some embodiments, the cell is from a biological sample of a subject, and wherein the method further comprises determining a presence or an absence of a condition or an attribute in the subject based on the analyzed image.

In a different aspect, the present disclosure provides a computer program product comprising a non-transitory computer-readable medium having computer-executable code encoded therein, the computer-executable code adapted to be executed to implement the method of sorting the cell.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications, and NCBI accession numbers mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, patent application, or NCBI accession number was specifically and individually indicated to be incorporated by reference. To the extent publications and patents, patent applications, or NCBI accession numbers incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and/or take precedence over any such contradictory material.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the disclosure are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the disclosure are utilized, and the accompanying drawings (also “Figure” and “FIG.” herein), of which:

FIG. 1A conceptually illustrates a classification and/or sorting system in accordance with one embodiment of the disclosure.

FIG. 1B conceptually illustrates a microfluidic design of a flow cell in accordance with one embodiment of the disclosure.

FIG. 2 conceptually illustrates an exemplary long flow channel with controlled length to ensure that the objects in the system arrive at the bifurcation exactly when the decision is made and valve actuation is completed.

FIG. 3 conceptually illustrates an exemplary three-branch channel design.

FIG. 4 conceptually illustrates a particle rotating as it moves through the channel.

FIG. 5 conceptually illustrates an out-of-focus cell and an in-focus cell using inertia-based z focusing.

FIG. 6 conceptually illustrates a non-limiting triple-punch design.

FIG. 7 conceptually illustrates the adaptive labeling framework.

FIG. 8 conceptually illustrates the modifications made to Resnet50, wherein early layers are elongated in exchange of shrinkage of late-stage layers, in order to enhance it and improve its accuracy.

FIG. 9 conceptually illustrates the multi-view ensemble inference framework.

FIG. 10 conceptually illustrates the multi-view to multi-channel data framework.

FIG. 11 conceptually illustrates a non-limiting sorting design.

FIG. 12 conceptually illustrates a non-limiting sorting design that uses piezo actuator.

FIG. 13 conceptually illustrates a non-limiting sorting design that uses magnetic actuation.

FIG. 14 conceptually illustrates a technique wherein the two lasers from the system of the present disclosure are recombined with a close proximity.

FIG. 15 conceptually illustrates a validation technique that comprises a backchannel design.

FIG. 16 shows a computer system that is programmed or otherwise configured to implement methods provided herein.

DETAILED DESCRIPTION

While various embodiments of the disclosure have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the disclosure. It should be understood that various alternatives to the embodiments of the disclosure described herein may be employed.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. In case of conflict, the present application including the definitions will control. Also, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

Classification and/or Sorting Systems

In an aspect, the present disclosure describes a cell sorting system. The cell sorting system can comprise a flow channel configured to transport a cell through the channel. The cell sorting system can comprise an imaging device configured to capture an image of the cell from a plurality of different angles as the cell is transported through the flow channel. The cell sorting system can comprise a processor configured to analyze the image using a deep learning algorithm to enable sorting of the cell. The cell sorting system can be a cell classification system. In some cases, the flow channel can be configured to transport a solvent (e.g., liquid, water, media, alcohol, etc.) without any cell. The cell sorting system can have one or more mechanisms (e.g., a motor) for moving the imaging device relative to the channel. Such movement can be relative movement, and thus the moving piece can be the imaging device, the channel, or both. The processor can be further configured to control such relative movement.

In some embodiments, the disclosure provides a classification and/or sorting system as illustrated in FIG. 1A shows a schematic illustration of the cell sorting system with a flow cell design (e.g., a microfluidic design), with further details illustrated in FIG. 1B. In operation, a sample 102 is prepared and injected by a pump 104 (e.g., a syringe pump) into a flow cell 106, or flow-through device. In some embodiments, the flow cell 106 is a microfluidic device. Although FIG. 1A illustrates a classification and/or sorting system utilizing a syringe pump, any of a number of perfusion systems can be used such as (but not limited to) gravity feeds, peristalsis, or any of a number of pressure systems. In some embodiments, the sample is prepared by fixation and staining. In some examples, the sample comprises live cells. As can readily be appreciated, the specific manner in which the sample is prepared is largely dependent upon the requirements of a specific application.

In some embodiments, a cell suspension sample is prepared at concentrations ranging between 1×10⁴-5×10⁶ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 1×10⁴-5×10⁴ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 5×10⁴-1×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 1×10⁵-5×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 5×10⁵-1×10⁶ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 1×10⁶-5×10⁶ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 5×10⁴-5×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 1×10⁴-5×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 5×10⁴-1×10⁶ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 2×10⁵-5×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 3×10⁵-5×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 4×10⁵-5×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 1×10⁵-4×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 2×10⁵-4×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 3×10⁵-4×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 1×10⁵-3×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 2×10⁵-3×10⁵ cells/mL. In some embodiments, a cell suspension sample is prepared at concentrations ranging between 1×10⁵-2×10⁵ cells/mL.

In some embodiments, a cell suspension sample is prepared at a concentration of about 1×10⁴ cells/mL, about 5×10⁴ cells/mL, about 1×10⁵ cells/mL, about 2×10⁵ cells/mL, about 3×10⁵ cells/mL, about 4×10⁵ cells/mL, about 5×10⁴ cells/mL, about 5×10⁵ cells/mL, about 1×10⁶ cells/mL, or about 5×10⁶ cells/mL.

The specific concentration utilized in a given classification and/or sorting system typically depends upon the capabilities of the system. Cells may be fixed and stained with colored dyes (e.g., Papanicolaou and Wright Giemsa methods). Classification and/or sorting systems in accordance with various embodiments of the disclosure can operate with live, fixed and/or Wright Giemsa-stained cells. Staining can help increase the contrast of nuclear organelles and improve classification accuracy. In some embodiments the cells in the sample are not labelled and/or stained. After preparation, the cell suspension sample can be injected into the microfluidic device using a conduit such as (but not limited to) tubing and a perfusion system such as (but not limited to) a syringe pump.

In some embodiments, a syringe pump injects the sample at about 10 μL/min. In some embodiments, a syringe pump injects the sample at about 50 μL/min. In some embodiments, a syringe pump injects the sample at about 100 μL/min. In some embodiments, a syringe pump injects the sample at about 150 μL/min. In some embodiments, a syringe pump injects the sample at about 200 μL/min. In some embodiments, a syringe pump injects the sample at about 250 μL/min. In some embodiments, a syringe pump injects the sample at about 500 μL/min. In some embodiments, a syringe pump injects the sample at about 10 μL/min to about 500 μL/min, for example at about 10 μL/min to about 50 μL/min, about 10 μL/min to about 100 μL/min, about 10 μL/min to about 150 μL/min, about 10 μL/min to about 200 μL/min, about 10 μL/min to about 250 μL/min, about 10 μL/min to about 300 μL/min, about 10 μL/min to about 350 μL/min, about 10 μL/min to about 400 μL/min, or about 10 μL/min to about 450 μL/min.

As can readily be appreciated, any perfusion system, including but not limited to peristalsis systems and gravity feeds, appropriate to a given classification and/or sorting system can be utilized.

As noted above, the flow cell 106 can be implemented as a fluidic device that focuses cells from the sample into a single streamline that is imaged continuously. In the illustrated embodiment, the cell line is illuminated by a light source 108 and an optical system 110 that directs light onto an imaging region 138 of the flow cell 106. An objective lens system 112 magnifies the cells by directing light toward the sensor of a high-speed camera system 114.

In some embodiments, a 10×, 20×, 40×, 60×, 80×, 100×, or 200× objective is used to magnify the cells. In some embodiments, a 10×, objective is used to magnify the cells. In some embodiments, a 20× objective is used to magnify the cells. In some embodiments, a 40× objective is used to magnify the cells. In some embodiments, a 60× objective is used to magnify the cells. In some embodiments, a 80× objective is used to magnify the cells. In some embodiments, a 100× objective is used to magnify the cells. In some embodiments, a 200× objective is used to magnify the cells. In some embodiments, a 10× to a 200× objective is used to magnify the cells, for example a 10×-20×, a 10×-40×, a 10×-60×, a 10×-80×, or a 10×-100× objective is used to magnify the cells.

As can readily be appreciated by a person having ordinary skill in the art, the specific magnification utilized can vary greatly and is largely dependent upon the requirements of a given imaging system and cell types of interest.

In some embodiments, one or more imaging devices (e.g., at least 1, 2, 3, 4, 5, or more imaging devices) may be used to capture images of the cell. In some aspects, the imaging device is a high-speed camera. In some aspects, the imaging device is a high-speed camera with a micro-second exposure time. In some instances, said exposure time is 1 millisecond. In some instances, said exposure time is between 1 millisecond (ms) and 0.75 millisecond. In some instances, said exposure time is between 1 ms and 0.50 ms. In some instances, said exposure time is between 1 ms and 0.25 ms. In some instances, said exposure time is between 0.75 ms and 0.50 ms. In some instances, said exposure time is between 0.75 ms and 0.25 ms. In some instances, said exposure time is between 0.50 ms and 0.25 ms. In some instances, said exposure time is between 0.25 ms and 0.1 ms. In some instances, said exposure time is between 0.1 ms and 0.01 ms. In some instances, said exposure time is between 0.1 ms and 0.001 ms. In some instances, said exposure time is between 0.1 ms and 1 microsecond (μs). In some aspects, said exposure time is between 1 μs and 0.1 μs. In some aspects, said exposure time is between 1 μs and 0.01 μs. In some aspects, said exposure time is between 0.1 μs and 0.01 μs. In some aspects, said exposure time is between 1 μs and 0.001 μs. In some aspects, said exposure time is between 0.1 μs and 0.001 μs. In some aspects, said exposure time is between 0.01 μs and 0.001 μs.

In some embodiments, image sequences from cells are recorded at rates of about 10 frames/sec to about 10,000,000 frames/sec. In some embodiments, image sequences from cells are recorded at rates of at least about 10 frames/sec. In some embodiments, image sequences from cells are recorded at rates of at most about 10,000,000 frames/sec. In some embodiments, image sequences from cells are recorded at rates of about 10 frames/sec to about 100 frames/sec, about 10 frames/sec to about 1,000 frames/sec, about 10 frames/sec to about 10,000 frames/sec, about 10 frames/sec to about 100,000 frames/sec, about 10 frames/sec to about 1,000,000 frames/sec, about 10 frames/sec to about 10,000,000 frames/sec, about 100 frames/sec to about 1,000 frames/sec, about 100 frames/sec to about 10,000 frames/sec, about 100 frames/sec to about 100,000 frames/sec, about 100 frames/sec to about 1,000,000 frames/sec, about 100 frames/sec to about 10,000,000 frames/sec, about 1,000 frames/sec to about 10,000 frames/sec, about 1,000 frames/sec to about 100,000 frames/sec, about 1,000 frames/sec to about 1,000,000 frames/sec, about 1,000 frames/sec to about 10,000,000 frames/sec, about 10,000 frames/sec to about 100,000 frames/sec, about 10,000 frames/sec to about 1,000,000 frames/sec, about 10,000 frames/sec to about 10,000,000 frames/sec, about 100,000 frames/sec to about 1,000,000 frames/sec, about 100,000 frames/sec to about 10,000,000 frames/sec, or about 1,000,000 frames/sec to about 10,000,000 frames/sec. In some embodiments, image sequences from cells are recorded at rates of about 10 frames/sec, about 100 frames/sec, about 1,000 frames/sec, about 10,000 frames/sec, about 100,000 frames/sec, about 1,000,000 frames/sec, or about 10,000,000 frames/sec.

In some embodiments, image sequences from cells are recorded at rates of between 10,000-10,000,000 frames/sec using a high-speed camera, which may be color, monochrome, and/or imaged using any of a variety of imaging modalities including (but not limited to) the near-infrared spectrum. In some embodiments, image sequences from cells are recorded at rates of between 50,000-5,000,000 frames/sec. In some embodiments, image sequences from cells are recorded at rates of between 50,000-100,000 frames/sec. In some embodiments, image sequences from cells are recorded at rates of between 100,000-1,000,000 frames/sec. In some embodiments, image sequences from cells are recorded at rates of between 100,000-500,000 frames/sec. In some embodiments, image sequences from cells are recorded at rates of between 500,000-1,000,000 frames/sec. In some embodiments, image sequences from cells are recorded at rates of between 1,000,000-5,000,000 frames/sec.

In some embodiments, image sequences from cells are recorded at a rate of about 50,000 frames/sec, about 100,000 frames/sec, about 200,000 frames/sec, about 300,000 frames/sec, about 400,000 frames/sec, about 500,000 frames/sec, about 750,000 frames/sec, about 1,000,000 frames/sec, about 2,500,000 frames/sec, about 5,000,000 frames/sec, or about 10,000,000 frames/sec.

In some embodiments, the imaging device used in the present disclosure is an ultra-high speed camera, wherein images are recorded at a rate of up to 25,000,000 frames/sec. In some instances, said ultra-high speed camera runs at 20,000 revolutions per second. In some instances, said high-speed camera has a resolution of 616×920 pixels.

The imaging device(s) (e.g., the high-speed camera) of the imaging system can comprise an electromagnetic radiation sensor (e.g., IR sensor, color sensor, etc.) that detects at least a portion of the electromagnetic radiation that is reflected by and/or transmitted from the flow cell or any content (e.g., the cell) in the flow cell. The imaging device can be in operative communication with one or more sources (e.g., at least 1, 2, 3, 4, 5, or more) of the electromagnetic radiation. The electromagnetic radiation can comprise one or more wavelengths from the electromagnetic spectrum including, but not limited to x-rays (about 0.1 nanometers (nm) to about 10.0 nm; or about 10¹⁸ Hertz (Hz) to about 10¹⁶ Hz), ultraviolet (UV) rays (about 10.0 nm to about 380 nm; or about 8×10¹⁶ Hz to about 10¹⁵ Hz), visible light (about 380 nm to about 750 nm; or about 8×10¹⁴ Hz to about 4×10¹⁴ Hz), infrared (IR) light (about 750 nm to about 0.1 centimeters (cm); or about 4×10¹⁴ Hz to about 5×10¹¹ Hz), and microwaves (about 0.1 cm to about 100 cm; or about 10⁸ Hz to about 5×10¹¹ Hz). In some cases, the source(s) of the electromagnetic radiation can be ambient light, and thus the cell sorting system may not have an additional source of the electromagnetic radiation.

The imaging device(s) can be configured to take a two-dimensional image (e.g., one or more pixels) of the cell and/or a three-dimensional image (e.g., one or more voxels) of the cell.

In some embodiment, the imaging area is illuminated with a high-power light-emitting diode (LED) with exposure times that is less than 1 millisecond (msec) to help prevent motion blurring of cells. In some embodiment, the imaging area is illuminated with a high-power LED with exposure times that is less than 1 microsecond (pec) to help prevent motion blurring of cells. In some embodiments the imaging device comprises a combination of a strobe light and a camera. Strobe light, strobe, stroboscopic lamp, and strobing light may be used interchangeably. In some instances, a strobe light is a device used to produce regular flashes of light. In some embodiments, a high-speed strobe light is used in combination with one or more cameras. In some instances, said high-speed strobe lights are capable of up to 2500 strobes per second. In some instances, said high-speed strobe lights are capable of up to 5000 strobes per second. In some instances, said high-speed strobe lights have a storage of electrical energy to pulse the LEDs wherein said energy can go up to 2000 watts when the LEDs are active. In some instances, said high-speed strobe light pulses the LED with up to 180 amps of DC current. In some instances, said strobe light is white. In some instances, said strobe light is blue with a wavelength of 470 nm. In some instances, said strobe light is green with a wavelength of 530 nm. In some instances, said strobe light is red with a wavelength of 625 nm. In some instances, said strobe light is infrared with a wavelength of 850 nm. In some embodiments, the imaging device comprises a combination of a strobe light and one or more cameras wherein said cameras are high-speed camera. In some embodiments, the imaging device comprises a combination of a high-speed strobe light and one or more cameras, wherein said cameras are high-speed cameras.

As can readily be appreciated, the exposure times can differ across different systems and can largely be dependent upon the requirements of a given application or the limitations of a given system such as but not limited to flow rates. Images are acquired and can be analyzed using an image analysis algorithm.

In some embodiments, the images are acquired and analyzed post-capture. In some aspects, the images are acquired and analyzed in real-time continuously. Using object tracking software, single cells can be detected and tracked while in the field of view of the camera. Background subtraction can then be performed. In a number of embodiments, the flow cell 106 causes the cells to rotate as they are imaged and multiple images of each cell are provided to a computing system 116 for analysis. In some embodiments, the multiple images comprise images from a plurality of cell angles.

The flow rate and channel dimensions can be determined to obtain multiple images of the same cell from a plurality of different angles (i.e., a plurality of cell angles). A degree of rotation between an angle to the next angle may be uniform or non-uniform. In some examples, a full 360° view of the cell is captured. In some embodiments, 4 images are provided in which the cell rotates 90° between successive frames. In some embodiments, 8 images are provided in which the cell rotates 45° between successive frames. In some embodiments, 24 images are provided in which the cell rotates 15° between successive frames. In some embodiments, at least three or more images are provided in which the cell rotates at a first angle between a first frame and a second frame, and the cell rotates at a second angle between the second frame and a third frame, wherein the first and second angles are different.

The cell can have a plurality sides. The plurality of sides of the cell can be defined with respect to a direction of the transport (flow) of the cell through the channel. In some cases, the cell can comprise a stop side, a bottom side that is opposite the top side, a front side (e.g., the side towards the direction of the flow of the cell), a rear side opposite the front side, a left side, and/or a right side opposite the left side. In some cases, the image of the cell can comprise a plurality of images captured from the plurality of angles, wherein the plurality of images comprise: (1) an image captured from the top side of the cell, (2) an image captured from the bottom side of the cell, (3) an image captured from the front side of the cell, (4) an image captured from the rear side of the cell, (5) an image captured from the left side of the cell, and/or (6) an image captured from the right side of the cell

In some embodiments, a two-dimensional “hologram” of a cell can be generated by superimposing the multiple images of the individual cell. The “hologram” can be analyzed to automatically classify characteristics of the cell based upon features including but not limited to the morphological features of the cell.

In some embodiments, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 images are captured for each cell. In some embodiments, 5 or more images are captured for each cell. In some embodiments, from 5 to 10 images are captured for each cell. In some embodiments, 10 or more images are captured for each cell. In some embodiments, from 10 to 20 images are captured for each cell. In some embodiments, 20 or more images are captured for each cell. In some embodiments, from 20 to 50 images are captured for each cell. In some embodiments, 50 or more images are captured for each cell. In some embodiments, from 50 to 100 images are captured for each cell. In some embodiments, 100 or more images are captured for each cell.

In some embodiments, the imaging device is moved so as to capture multiple images of the cell from a plurality of angles. In some aspects, said images are captured at an angle between 0 and 90 degrees to the horizontal axis. In some aspects, said images are captured at an angle between 90 and 180 degrees to the horizontal axis. In some aspects, said images are captured at an angle between 180 and 270 degrees to the horizontal axis. In some aspects, said images are captured at an angle between 270 and 360 degrees to the horizontal axis.

In some embodiments, multiple imaging devices (for e.g. multiple cameras) are used wherein each device captures an image of the cell from a specific cell angle. In some aspects, 2, 3, 4, 5, 6, 7, 8, 9, or 10 cameras are used. In some aspects, more than 10 cameras are used, wherein each camera images the cell from a specific cell angle,

As can readily be appreciated, the number of images that are captured is dependent upon the requirements of a given application or the limitations of a given system. In several embodiments, the flow cell has different regions to focus, order, and/or rotate cells. Although the focusing regions, ordering regions, and cell rotating regions are discussed as affecting the sample in a specific sequence, a person having ordinary skill in the art would appreciate that the various regions can be arranged differently, where the focusing, ordering, and/or rotating of the cells in the sample can be performed in any order. Regions within a microfluidic device implemented in accordance with an embodiment of the disclosure are illustrated in FIG. 1B. Flow cell 106 may include a filtration region 130 to prevent channel clogging by aggregates/debris or dust particles. Cells pass through a focusing region 132 that focuses the cells into a single streamline of cells that are then spaced by an ordering region 134. In some embodiments, the focusing region utilizes “inertial focusing” to form the single streamline of cells. In some embodiments, the focusing region utilizes ‘hydrodynamic focusing” to focus the cells into the single streamline of cells. Optionally, prior to imaging, rotation can be imparted upon the cells by a rotation region 136. The optionally spinning cells can then pass through an imaging region 138 in which the cells are illuminated for imaging prior to exiting the flow cell. These various regions are described and discussed in further detail below.

In some embodiments, a single cell is imaged in a field of view of the imaging device, e.g. camera. In some embodiments, multiple cells are imaged in the same field of view of the imaging device. In some aspects, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 cells are imaged in the same field of view of the imaging device. In some aspects, up to 100 cells are imaged in the same field of view of the imaging device. In some instances, 10 to 100 cells are imaged in said field of view, for example, 10 to 20 cells, 10 to 30 cells, 10 to 40 cells, 10 to 50 cells, 10 to 60 cells, 10 to 80 cells, 10 to 90 cells, 20 to 30 cells, 20 to 40 cells, 20 to 50 cells, 20 to 60 cells, 20 to 70 cells, 20 to 80 cells, 20 to 90 cells, 30 to 40 cells, 40 to 50 cells, 40 to 60 cells, 40 to 70 cells, 40 to 80 cells, 40 to 90 cells, 50 to 60 cells, 50 to 70 cells, 50 to 80 cells, 50 to 90 cells, 60 to 70 cells, 60 to 80 cells, 60 to 90 cells, 70 to 80 cells, 70 to 90 cells, 90 to 100 cells are imaged in the same field of view of the imaging device.

In some cases, only a single cell may be allowed to be transported across a cross-section of the flow channel perpendicular to the axis of the flow channel. In some cases, a plurality of cells (e.g., at least 2, 3, 4, 5, or more cells) may be allowed to be transported simultaneously across the cross-section of the flow channel perpendicular to the axis of the flow channel. In such a case, the imaging device (or the processor operatively linked to the imaging device) may be configured to track each of the plurality of cells as they are transported along the flow channel.

In some embodiments, the classification and/or sorting systems in accordance with various embodiments of the disclosure eliminate the variability involved in manual preparation of slides, which rely on expertise of the operator. Furthermore, image segmentation can be avoided. The classification and/or sorting system allows for high flow rates and high-throughputs can be achieved.

In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate of at least 100 cells/second and a computing system that can classify at a rate of at least 100 cells/second. In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate of at least 500 cells/second and a computing system that can classify at a rate of at least 500 cells/second. In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate of at least 1000 cells/second and a computing system that can classify at a rate of at least 1000 cells/second. In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate of at least 2000 cells/second and a computing system that can classify at a rate of at least 2000 cells/second. In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate of at least 5000 cells/second and a computing system that can classify at a rate of at least 5000 cells/second. In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate of at least 10,000 cells/second and a computing system that can classify at a rate of at least 10,000 cells/second.

In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate that is equal up to 100 cells/second and a computing system that can classify up to 100 cells/second. In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate that is equal up to 500 cells/second and a computing system that can classify up to 500 cells/second. In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate that is equal to up to 1000 cells/second and a computing system that can classify up to 1000 cells/second. In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate that is equal to up to 2000 cells/second and a computing system that can classify up to 2000 cells/second. In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate that is equal to up to 5000 cells/second and a computing system that can classify up to 5000 cells/second. In some embodiments, the classification and/or sorting system includes an imaging system that can capture images at a rate that is equal to up to 10,000 cells/second and a computing system that can classify up to 10,000 cells/second.

The imaging system can include, among other things, a camera, an objective lens system and a light source. In a number of embodiments, flow cells similar to those described above can be fabricated using standard 2D microfluidic fabrication techniques, requiring minimal fabrication time and cost.

Although specific classification and/or sorting systems, flow cells, and microfluidic devices are described above with respect to FIGS. 1A and 1B, classification and/or sorting systems can be implemented in any of a variety of ways appropriate to the requirements of specific applications in accordance with various embodiments of the disclosure. Specific elements of microfluidic devices that can be utilized in classification and/or sorting systems in accordance with some embodiments of the disclosure are discussed further below.

Microfluidic Device Fabrication

Microfluidic devices in accordance with several embodiments of the disclosure can be fabricated using a variety of methods. In some embodiments, a combination of photolithography and mold casting is used to fabricate a microfluidic device. Conventional photolithography typically involves the use of photoresist and patterned light to create a mold containing a positive relief of the desired microfluidic pattern on top of a substrate, typically a silicon wafer. Photoresist is a photo-curable material that can be used in photolithography to create structures with feature sizes on the order of micrometers (μm). During fabrication, the photoresist can be deposited onto a substrate. The substrate can be spun to create a layer of photoresist with a targeted desired height. The photoresist layer can then be exposed to light, typically UV light (depending on the type of photoresist), through a patterned mask to create a cured pattern of photoresist. The remaining uncured portions can be developed away, leaving behind a positive relief mold that can be used to fabricate microfluidic devices.

From the mold, material can be cast to create a layer containing a negative relief pattern. Inlet and outlet holes can be formed at appropriate regions, and the device can then be bonded to a backing to create a flow-through device, or flow cell, with flow channels (e.g., microfluidic channels). A cross-section of the flow channel can have a width and a height. The cross-section may be perpendicular to an axis of the flow channel (e.g., a direction of the flow of the solvent with or without cells inside the flow channel). The width and the height of the flow channel can be perpendicular to each other. The width and/or the height of the flow channel can be uniform or non-uniform along the axis of the flow channel. In some cases, the width or the height of the flow channel can increase or decrease (e.g., gradually or rapidly) along a direction of the flow channel through which the cell is transported. In some cases, the width or the height of the flow channel can increase along a section of the flow channel, and decrease along a different section of the flow channel.

The width or the height of the cross-section of the flow channel can be about 1 μm to about 500 μm. The width or the height of the cross-section of the flow channel can be at least about 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, or more. The width or the height of the cross-section of the flow channel can be at most about 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, 90 μm, 0 μm, 0 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 10 μm, 9 μm, 8 μm, 7 μm, 6 μm, 5 μm, 4 μm, 3 μm, 2 μm, 1 μm, or less.

The width or the height of the channel can increase or decrease along the direction of the flow channel at about 0.01 percent per μm (%/μm) to about 1000%/μm. The increase of decrease of the width or height of the channel along the direction of the flow channel can be at least about 0.01%/μm, 0.05%/μm, 0.1%/μm, 0.5%/μm, 1%/μm, 5%/μm, 10%/μm, 50%/μm, 100%/μm, 500%/μm, 1000%/μm, or more. The increase of decrease of the width or height of the channel along the direction of the flow channel can be at most about 1000%/μm, 500%/μm, 100%/μm, 50%/μm, 10%/μm, 5%/μm, 1%/μm, 0.5%/μm, 0.1%/μm, 0.05%/μm, 0.01%/μm, or less.

In some embodiments, the system of the present disclosure comprises straight channels with rectangular or square cross-sections. In some aspects, the system of the present disclosure comprises straight channels with round cross-sections. In some aspects, said system comprises straight channels with half-ellipsoid cross-sections. In some aspects, said system comprises spiral channels. In some aspects, said system comprises round channels with rectangular cross-sections. In some aspects, said system comprises round channels with rectangular channels with round cross-sections. In some aspects, said system comprises round channels with half-ellipsoid cross-sections. In some aspects, said system comprises channels that are expanding and contracting in width with rectangular cross-sections. In some aspects, said system comprises channels that are expanding and contracting in width with round cross-sections. In some aspects, said system comprises channels that are expanding and contracting in width with half-ellipsoid cross-sections.

In some embodiments utilizing a rotation section, a two-layer fabrication process can be used to orient the rotation section so that imaging of the cells as they rotate will provide images of cells at different angles with a more accurate representation of cellular features.

As can be readily appreciated, the microfluidic device can be fabricated using a variety of materials as appropriate to the requirements of the given application. In imaging applications, the microfluidic device is typically made of an optically transparent material such as (but not limited to) polydimethylsiloxane (PDMS). In some embodiments, the microfluidic device is made of silicon. In some embodiments, the microfluidic device is made of low-temperature cofired ceramic (LTCC). In some embodiments, the microfluidic device is made of thermoset polyester (TPE). In some embodiments, the microfluidic device is made of polystyrene (PS). In some embodiments, the microfluidic device is made of polycarbonate (PC). In some embodiments, the microfluidic device is made of poly-methyl methacrylate (PMMA). In some embodiments, the microfluidic device is made of poly(ethylene glycol) diacrylate (PEGDA). In some embodiments, the microfluidic device is made of polyfluoropolyether diol methacrylate (PFPE-DMA). In some embodiments, the microfluidic device is made of polyurethane (PU).

Although a specific method of microfluidic device fabrication is discussed, any of a variety of methods can be implemented to fabricate a microfluidic device utilized in accordance with various embodiments of the disclosure as appropriate to the requirements of a given application.

Microfluidic Filters

Microfluidic devices in accordance with several embodiments of the disclosure can include one or more microfluidic filters at the inlets, or further down, of the microfluidic device to prevent channel clogging. In other embodiments, filtration can occur off device. The specific dimensions and patterns of the filters and the microfluidic channel can vary and are largely dependent upon the sizes of the cells of interest and the requirements of a given application. Any of a variety of microfluidic filter systems can be implemented on microfluidic devices utilized in accordance with various embodiments of the disclosure as appropriate to the requirements of a given flow application.

Focusing Regions

The flow channel can comprise one or more walls that are formed to focus one or more cells into a streamline. The flow channel can comprise a focusing region comprising the wall(s) to focus the cell(s) into the streamline. Focusing regions on a microfluidic device can take a disorderly stream of cells and utilize a variety of forces (for e.g. inertial lift forces (wall effect and shear gradient forces) or hydrodynamic forces) to focus the cells within the flow into a streamline of cells. In some embodiments, the cells are focused in a single streamline. In some examples, the cells are focused in multiple streamlines, for example at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 streamlines.

The focusing region receives a flow of randomly arranged cells via an upstream section. The cells flow into a region of contracted and expanded sections in which the randomly arranged cells are focused into a single streamline of cells. The focusing is driven by the action of inertial lift forces (wall effect and shear gradient forces) acting on cells at Reynolds numbers>1, where channel Reynolds number is defined as follows: Re_(c)=ρU_(m)W/μ, where U_(m) is the maximum fluid velocity, ρ is the fluid density, μ is the fluid viscosity, and W is the channel dimension. In some embodiments, Reynolds numbers around 20-30 can be used to focus particles from about 10 μm to about 20 μm. In some embodiments, the Reynolds number is such that laminar flow occurs within the microfluidic channels. As can readily be appreciated, the specific channel Reynolds number can vary and is largely determined by the characteristics of the cells for which the microfluidic device is designed, the dimensions of the microfluidic channels, and the flow rate controlled by the perfusion system.

In some embodiments, the focusing region is formed with curvilinear walls that form periodic patterns. In some embodiments, the patterns form a series of square expansions and contractions. In other embodiments, the patterns are sinusoidal. In further embodiments, the sinusoidal patterns are skewed to form an asymmetric pattern. The focusing region can be effective in focusing cells over a wide range of flow rates. In the illustrated embodiment, an asymmetrical sinusoidal-like structure is used as opposed to square expansions and contractions. This helps prevent the formation of secondary vortices and secondary flows behind the particle flow stream. In this way, the illustrated structure allows for faster and more accurate focusing of cells to a single lateral equilibrium position. Spiral and curved channels can also be used in an inertia regime; however, these can complicate the integration with other modules. Finally, straight channels where channel width is greater than channel height can also be used for focusing cells onto single lateral position. However, in this case, since there will be more than one equilibrium position in the z-plane, imaging can become problematic, as the imaging focal plane is preferably fixed. As can readily be appreciated, any of a variety of structures that provide a cross section that expands and contracts along the length of the microfluidic channel or are capable of focusing the cells can be utilized as appropriate to the requirements of specific applications.

The cell sorting system can be configured to focus the cell at a width and/or a height within the flow channel along an axis of the flow channel. The cell can be focused to a center or off the center of the cross-section of the flow channel. The cell can be focused to a side (e.g., a wall) of the cross-section of the flow channel. A focused position of the cell within the cross-section of the channel may be uniform or non-uniform as the cell is transported through the channel.

While specific implementations of focusing regions within microfluidic channels are described above, any of a variety of channel configurations that focus cells into a single streamline can be utilized as appropriate to the requirements of a specific application in accordance with various embodiments of the disclosure.

Ordering Regions

Microfluidic channels can be designed to impose ordering upon a single streamline of cells formed by a focusing region in accordance with several embodiments of the disclosure. Microfluidic channels in accordance with some embodiments of the disclosure include an ordering region having pinching regions and curved channels. The ordering region orders the cells and distances single cells from each other to facilitate imaging. In some embodiments, ordering is achieved by forming the microfluidic channel to apply inertial lift forces and Dean drag forces on the cells. Dean flow is the rotational flow caused by fluid inertia. The microfluidic channel can be formed to create secondary flows that apply a Dean drag force proportional to the velocity of the secondary flows. Dean drag force scales with about ρU_(m) ²αD_(h) ²/R, where ρ is the fluid density, Um is the maximum fluid velocity,

D_(h)=2WH(W+H) is the channel hydraulic diameter, α is the particle dimension, and R is the curvature radius. The force balance between inertial lift and Dean drag forces determines particle equilibrium position.

Depending on the particle size, the relative interior and exterior radii of curvature (R_(lin,out)) of the channel and channel height (H_(C)) of the microfluidic channel can be determined to reach equilibrium at desired locations. Different combinations of curved and pinching regions (and their parameters) can be used to achieve desired distance between particles. Channel width in the pinching region can be adjusted such that the cells will not be squeezed through the channels, causing possible damage to the cell membrane (the cells can, however, be slightly deformed without touching the channel walls while traveling through the pinching regions). Additionally, the squeezing could cause debris/residues from cell membrane left on the channel walls, which will change the properties of the channel. The ordering in the pinching regions is driven by instantaneous change in channel fluidic resistance upon arrival of a cell/particle. Since the channel width in this region is close to cell/particle dimensions, when a cell arrives at the pinching region, the channel resistance increases. Since the whole system is pressure-regulated (constant pressure), this can cause an instantaneous decrease in flow rate and therefore spacing of the cells. The length and width of pinching region can be adjusted to reach desired spacing between cells. The curved channel structure can also help with focusing cells to a single z position, facilitating imaging.

Different geometries, orders, and/or combinations can be used. In some embodiments, pinching regions can be placed downstream from the focusing channels without the use of curved channels. Adding the curved channels helps with more rapid and controlled ordering, as well as increasing the likelihood that particles follow a single lateral position as they migrate downstream. As can readily be appreciated, the specific configuration of an ordering region is largely determined based upon the requirements of a given application.

Cell Rotating Regions

Microfluidic channels can be configured to impart rotation on ordered cells in accordance with a number of embodiments of the disclosure. Cell rotation regions of microfluidic channels in accordance with some embodiments of the disclosure use co-flow of a particle-free buffer to induce cell rotation by using the co-flow to apply differential velocity gradients across the cells. In several embodiments, the cell rotation region of the microfluidic channel is fabricated using a two-layer fabrication process so that the axis of rotation is perpendicular to the axis of cell downstream migration and parallel to cell lateral migration. Cells are imaged in this region while tumbling and rotating as they migrate downstream. This allows for the imaging of a cell at different angles, which provides more accurate information concerning cellular features than can be captured in a single image or a sequence of images of a cell that is not rotating to any significant extent. This also allows for a 3D reconstruction of the cell using available software since the angles of rotation across the images are known. In some embodiments, a similar change in velocity gradient across the cell is achieved by providing a change in channel height (i.e. the dimension that is the smaller of the two dimensions of the cross section of the microfluidic channel and the dimension perpendicular to the imaging plane). This increase in channel height should be such that the width continues to be greater than the height of the channel. Also in the case of increasing channel height, there can be a shift in cell focusing position in the height dimension, which should be accounted for during imaging and adjustment of the imaging focal plane.

In some embodiments, a cell rotation region of a microfluidic channel incorporates an injected co-flow prior to an imaging region in accordance with an embodiment of the disclosure. Co-flow may be introduced in the z plane (perpendicular to the imaging plane) to spin the cells. Since the imaging is done in the x-y plane, rotation of cells around an axis parallel to the y-axis provides additional information by rotating portions of the cell that may have been occluded in previous images into view in each subsequent image. Due to a change in channel dimensions, at point x₀, a velocity gradient is applied across the cells, which can cause the cells to spin. The angular velocity of the cells depends on channel and cell dimensions and the ratio between Q1 (main channel flow rate) and Q2 (co-flow flow rate) and can be configured as appropriate to the requirements of a given application. In some embodiments, a cell rotation region incorporates an increase in one dimension of the microfluidic channel to initiate a change in the velocity gradient across a cell to impart rotation onto the cell. In some aspects, a cell rotation region of a microfluidic channel incorporates an increase in the z-axis dimension of the cross section of the microfluidic channel prior to an imaging region in accordance with an embodiment of the disclosure. The change in channel height can initiate a change in velocity gradient across the cell in the z axis of the microfluidic channel, which can cause the cells to rotate as with using co-flow.

Although specific techniques for imparting velocity gradients upon cells are described above, any of a variety of techniques can be utilized to impart rotation on a single streamline of cells as appropriate to the requirements of specific applications in accordance with various embodiments of the disclosure.

Flowing Cells

In some embodiments, the system and methods of the present disclosure focuses the cells in microfluidic channels. The term focusing as used herein broadly means controlling the trajectory of cell/cells movement and comprises controlling the position and/or speed at which the cells travel within the microfluidic channels. In some embodiments controlling the lateral position and/or the speed at which the particles travel inside the microfluidic channels, allows to accurately predict the time of arrival of the cell at a bifurcation. The cells may then be accurately sorted. The parameters critical to the focusing of cells within the microfluidic channels include, but are not limited to channel geometry, particle size, overall system throughput, sample concentration, imaging throughput, size of field of view, and method of sorting.

In some embodiments the focusing is achieved using inertial forces. In some embodiments, the system and methods of the present disclosure focus cells to a certain height from the bottom of the channel using inertial focusing (Dino Di Carlo, 2009, Lab on a Chip). In these embodiments, the distance of the cells from the objective is equal and images of all the cells will be clear. As such, cellular details, such as nuclear shape, structure, and size appear clearly in the outputted images with minimal blur. In some aspects, the system disclosed herein has an imaging focusing plane that is adjustable. In some aspects, the focusing plane is adjusted by moving the objective or the stage. In some aspects, the best focusing plane is found by recording videos at different planes and the plane wherein the imaged cells have the highest Fourier magnitude, thus, the highest level of detail and highest resolution, is the best plane (FIG. 5).

In some embodiments, the system and methods of the present disclosure utilize a hydrodynamic-based z focusing system to obtain a consistent z height for the cells of interests that are to be imaged. In some aspects, said design comprises hydrodynamic focusing using multiple inlets for main flow and side flow. In some aspects, said hydrodynamic-based z focusing system is a triple-punch design (FIG. 6). In some aspects, said design comprises hydrodynamic focusing with three inlets, wherein the two side flows pinch cells at the center. For certain channel designs, dual z focus points may be created, wherein a double-punch design similar to the triple-punch design may be used to send objects to one of the two focus points to get consistent focused images. In some aspects, said design comprises hydrodynamic focusing with 2 inlets, wherein only one side flow channel is used and cells are focused near channel wall. In some aspects, said hydrodynamic focusing comprises side flows that do not contain any cells and a middle inlet that contains cells. The ratio of the flow rate on the side channel to the flow rate on the main channel determines the width of cell focusing region. In some aspects, said design is a combination of the above. In all aspects, said design is integrable with the bifurcation and sorting mechanisms disclosed herein. In some aspects, said hydrodynamic-based z focusing system is used in conjunction with inertia-based z focusing.

In some embodiments, the terms “particles”, “objects”, and “cells” are used interchangeably. In some aspects, said cell is a live cell. In some aspects, said cell is a fixed cell.

Method to Control Particle Arrival Times

In various embodiments, the systems and methods of the present disclosure sort the cells by ensuring that the cells in the system arrive at the bifurcation exactly when the decision is made and valve actuation is completed. In some aspects, ensuring that the objects arrive at the bifurcation exactly when the decision is made and the valve actuation is completed is achieved by controlling length of the microfluidic channels. In some embodiments the channel is a long channel and the length of the channel is determined based on factors that include, but are not limited to, (i) the estimated time of decision making, (ii) latency and opening window of switching mechanism, such as valves, and (iii) velocity of the particles (FIG. 2).

In some embodiments, ensuring that the objects arrive at the bifurcation exactly when the decision is made and the valve actuation is completed is achieved by controlling the velocity of the cells. In some examples, this is achieved by branching the microfluidic channels. In these examples one or more branches are used to guide the fluid into one or more of multiple channels, thereby dropping the velocity of fluid and particles in any one channel while keeping particles in focus. In some aspects, the factor by which the velocity is dropped depends on parameters including but limited to number of channels, relative width of channels, and/or relative height of channels. An exemplary snapshot of a 3-branch design with particles focused to center is shown in (FIG. 3). In some embodiments the microfluidic channel is divided into 2, 3, 4, 5, 6, 7, 8, 9, or 10 branches.

In some embodiments, ensuring that the particles arrive at the bifurcation exactly when the decision is made and the valve actuation is completed is achieved by a gradual increase in width and/or height of the channel. In these examples, the velocity of particles can be decreased in a controlled manner guiding the particles into a wider and/or taller channel. In some embodiments, the angle and/or length of expansion are designed to avoid particles from changing trajectory. This will prevent the particles from getting out of focus.

In some embodiments, ensuring that the particles arrive at the bifurcation exactly when the decision is made and the valve actuation is completed is achieved by designs within the microfluidic channels. Such designs include but are not limited to curved and/or spiral designs that can delay particles before they arrive at bifurcation, while keeping their lateral positions as well as their relative longitudinal position to each other constant and controlled.

In some aspects, the methods and the systems disclosed herein ensure that the particles arrive at the bifurcation exactly when the decision is made and valve actuation is completed, as well as ensure that the lateral position of the particles upon their arrival is controlled.

Imaging and Classification

A variety of techniques can be utilized to classify images of cells captured by classification and/or sorting systems in accordance with various embodiments of the disclosure. In some embodiments, the image captures are saved for future analysis/classification either manually or by image analysis software. Any suitable image analysis software can be used for image analysis. In some embodiments, image analysis is performed using OpenCV. In some embodiments, analysis and classification is performed in real time. In some embodiments images are captured at frame rates between 10-10,000,000 frames per second, for example between 10 frames/sec to about 100 frames/sec, about 10 frames/sec to about 1,000 frames/sec, about 10 frames/sec to about 10,000 frames/sec, about 10 frames/sec to about 100,000 frames/sec, about 10 frames/sec to about 1,000,000 frames/sec, about 10 frames/sec to about 10,000,000 frames/sec, about 100 frames/sec to about 1,000 frames/sec, about 100 frames/sec to about 10,000 frames/sec, about 100 frames/sec to about 100,000 frames/sec, about 100 frames/sec to about 1,000,000 frames/sec, about 100 frames/sec to about 10,000,000 frames/sec, about 1,000 frames/sec to about 10,000 frames/sec, about 1,000 frames/sec to about 100,000 frames/sec, about 1,000 frames/sec to about 1,000,000 frames/sec, about 1,000 frames/sec to about 10,000,000 frames/sec, about 10,000 frames/sec to about 100,000 frames/sec, about 10,000 frames/sec to about 1,000,000 frames/sec, about 10,000 frames/sec to about 10,000,000 frames/sec, about 100,000 frames/sec to about 1,000,000 frames/sec, about 100,000 frames/sec to about 10,000,000 frames/sec, or about 1,000,000 frames/sec to about 10,000,000 frames/sec and classification is performed in real time. In some embodiments images are captured at frame rates between 100,000 and 500,000 frames per second and classification is performed in real time. In some aspects, images are captured at frame rates between 200,000 and 500,000 frames per second and classification is performed in real time. In some aspects, images are captured at frame rates between 300,000 and 500,000 frames per second and classification is performed in real time. In some aspects, images are captured at frame rates between 300,000 and 500,000 frames per second and classification is performed in real time. In some aspects, images are captured at frame rates between 400,000 and 500,000 frames per second and classification is performed in real time.

In some embodiments, the objects placed in the system disclosed herein flow at very high speeds through the channels of said system in order to maintain a high throughput and highly effective inertia focusing. In some aspects, the system of the present disclosure comprises a very high-speed camera with microsecond exposure time to decrease blur in outputted images. In some aspects, said high-speed camera captures images at frame rates between 200,000 and 500,000 frames per second. In some aspects, said high-speed camera captures images at frame rates between 300,000 and 500,000 frames per second. In some aspects, said high-speed camera captures images at frame rates between 300,000 and 500,000 frames per second. In some aspects, said high-speed camera captures images at frame rates between 400,000 and 500,000 frames per second. In some aspects, said system comprises a high-speed strobing light. In some aspects, said system comprises a high-speed strobing light with a slower camera, wherein multiple snapshots of the same object may be imaged onto one image frame (e.g., a single image frame), which may be and separated later with the feature extraction and classification algorithm disclosed herein.

In some embodiments, the system and methods of the present disclosure comprise collecting a plurality of images of objects in the flow. In some aspects, said plurality of images comprises at least 20 images of cells. In some aspects, said plurality of images comprises at least 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, or 2 images of cells. In some embodiments, the plurality of images comprises images from multiple cell angles. In some aspects, said plurality of images, comprising images from multiple cell angles, help derive extra features from the particle which would typically be hidden if the particle is imaged from a single point-of-view. In some examples, the microfluidic system, wherein said system forces result in the particle rotating as it moves through the microfluidic channel (FIG. 4).

In some embodiments, the systems and methods of present disclosure allow for a tracking ability, wherein said system and methods track a particle (e.g., cell) under the camera and maintain the knowledge of which frames belong to the same particle. In some embodiments, the particle is tracked until it has been classified and/or sorted.

In some embodiments, the systems and methods of the disclosure comprise imaging a single particle in a particular field of view of the camera. In some aspects, the system and methods of the present disclosure image multiple particles in the same field of view of camera. Imaging multiple particles in the same field of view of the camera can provide additional advantages, for example it will increase the throughput of the system by batching the data collection and transmission of multiple particles. In some instances, about 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 particles are imaged in the same field of view of the camera. In some instances, 100 to 200 particles are imaged in the same field of view of the camera

Feature Extraction and Classification

In some embodiments, the analysis of the images and/or classification of the particles are performed manually, for example by a human being. In some embodiments, the classification is performed by one or more classifiers. In some embodiments, the classifier is an automated classifier. In some embodiments, the classifier is trained to perform outcome determination based on cell feature and/or pattern recognition. The cell features and/or cell patterns include, but are not limited to, recognition of cell shape, cell diameter, nuclear shape, nuclear diameter, nuclear texture, nuclear edges, nuclear area, nuclear average intensity, nucleus to cytoplasm ratio, cell texture, cell edges, cell area, cell average intensity, DNA content (pgDNA) of the cells and/or the like.

In some embodiments, the one or more classifiers used in the system and methods of the present disclosure are trained using an adaptive labeling approach. In such training approach a classifier is first trained with a first set of known cells. The classifier is then allowed to classify cells in a second set of cells, such that the classifier classifies each cell in the second set of cells with a classification probability, wherein the classification probability is a representation of the classifier's certainty about the classification of a particular cell. After the classification of the second set of cells, cells classified with a classification probability lower than a predefined threshold are selected. These selected cells will represent cases where the classifier is “unsure” about the class. In some cases, this uncertainty may be due to sparsity of that particular type of cells in the first set of known cells. Once, the cells classified with a lower than the pre-defined threshold have been selected, the classifier is trained in a next round to classify these selected cells. In some embodiments, these steps can be repeated till a majority of cells, for e.g. greater than 50% of cells, greater than 55% of cells, greater than 60% of cells, greater than 65% of cells, greater than 70% of cells, greater than 75% of cells, greater than 80% of cells, greater than 85% of cells, greater than 90% of cells, greater than 91% of cells, greater than 91% of cells, greater than 92% of cells, greater than 93% of cells, greater than 94% of cells, greater than 95% of cells, greater than 96% of cells, greater than 97% of cells, greater than 98% of cells, greater than 99% of cells, or 100% of cells are classified with the classification probability equal to or greater than a predefined threshold. The technique is outlined in FIG. 7.

In some examples, the predefined threshold is a classification probability of greater than 0.50. In some examples, the predefined threshold is a classification probability that is greater than 0.60. In some examples, the predefined threshold is a classification probability that is greater than 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, or greater than 0.99. In some instances, the threshold probability is a classification probability of 1. In various embodiments, the classification probability is calculated based on validation tests. The validations tests can range from biological validations to software and simulation validations.

In some embodiments, the systems and methods disclosed herein use enhanced neural network designed specifically for cell image classification, for e.g. for single cell image classification. Accordingly, provided herein is a general framework that modifies a convolution neural architecture for single cell image classification. In some aspects, said enhanced neural network is designed by modification of known neural networks designed to work well with ordinary images, such as the image-net. In some aspects the enhanced neural networks are designed by the modification of neural networks such as AlexNet, VGGNet, GoogLeNet, ResNet (residual networks), DenseNet, and Inception networks. In some examples, the enhanced neural networks are designed by modification of ResNet (e.g. ResNet 18, ResNet 34, ResNet 50, ResNet 101, and ResNet 152) or inception networks. In some aspects, the modification comprises a series of network surgery operations that are mainly carried out to improve including inference time and/or inference accuracy.

In some embodiments the modification of the known neural networks comprises shrinking one or more late stage layers of the known neural network. In some example, shrinking the one or more late stage layers results in improved inference time of the neural network. In some instances, later-stage layers play less important roles in cell image data due to the visual features in cell images having lower complexity than objects found in image-net set or similar datasets.

In some aspects, shrinkage of late-stage layers may result in an accuracy loss. In some embodiments, such loss may be compensated at least partially by the addition of back hidden layers to earlier parts of the network. In some examples, shrinking the late stage layers and adding them to an earlier part of the neural network improves accuracy of the classifier even more than keeping them in the late layers.

In various examples, the early vs. late layers are distinguished by their distance to the input layer and/or

An exemplary enhanced neural network designed by the methods disclosed herein is shown in FIG. 8. The exemplary enhanced neural network is designed by modification of a residual learning network known as ResNet 50. In the modification exemplified, one block of 512 depth and two blocks of 256 depth, both of which are late stage residual layers are removed, and one block is added to the 128 block, which comes earlier in the network. In this particular example, the removal of late stage blocks improved the inference time, and the addition of the 128 depth block gained back and even improved the inference accuracy which was initially feasible with the standard ResNet 50.

In some embodiments, the use of the enhanced neural networks as disclosed herein improves the inference time, wherein the increase in the inference time is calculated as a percent increase using the formula: Percentage increase in the inference time=(inference time using the enhanced neural network-inference time using the known neural network)/inference time using the known neural network×100. In some embodiments, the use of the enhanced neural networks as disclosed herein improves the inference time by at least 10% as compared to the inference time with the known network the enhanced network is derived from. In some examples, the inference time is improved by at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 100%, at least 150%, at least 200%, at least 250%, at least 300%, at least 350%, at least 400%, at least 450%, at least 500%. In some embodiments, the inference accuracy of the enhanced neural networks is improved by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 100%, at least 150%, at least 200%, at least 250%, at least 300%, at least 350%, at least 400%, at least 450%, at least 500%.

In some embodiments, the accuracy of the system and/or methods disclosed herein is improved by using multiple images belonging to the same cell to assist and increase the accuracy of a classifier. FIG. 9 illustrates this embodiment. In some embodiments, the multiple images comprise images obtained from multiple cell angles. In some embodiments, the images from the multiple cell angles are captured as the cell is rotation in the microfluidic channel. In some embodiments, the images from multiple cell angles are captured by moving one or more imaging devices as the particle passes through the microfluidic channel. In some embodiments, the images from multiple cell angles are captured by multiple imaging devices positioned to capture particle images from specific particle angles.

In some embodiments, the accuracy of the systems and methods disclosed herein is further improved by utilizing ensemble methods for classification. The ensemble methods disclosed herein use a set of classifiers which have been trained based on different neural networks, with different initial conditions, etc. The set of classifiers are then allowed to classify the particle and the results from each of the classifier in the set of classifiers are aggregated to determine a final classification of the particle. In some embodiments at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 classifiers are used.

In some embodiments, the system and methods of the present disclosure leverage the multi-view nature of the acquired data by concatenating images obtained from multiple cell angles in a single training or inference procedure to the classifier. In some aspects, said concatenating is similar to that carried out in traditional neural nets to concatenate red green blue (RGB) colors. In some aspects, the present disclosure concatenates separate images belonging to the same cell or particle, wherein both training and classification procedures are sped up since only one inference operation is carried out per cell. FIG. 10 illustrates this embodiment.

Sorting

In some embodiments, the systems and the methods of the present disclosure actively sorts a stream of particles. The term sort or sorting as used herein refers to physically separating particles, for e.g. cells, with one or more desired characteristics. The desired characteristic(s) can comprise a feature of the cell(s) analyzed and/or obtained from the image(s) of the cell. Examples of the feature of the cell(s) can comprise a size, shape, volume, electromagnetic radiation absorbance and/or transmittance (e.g., fluorescence intensity, luminescence intensity, etc.), or viability (e.g., when live cells are used).

The flow channel can branch into a plurality of channels, and the cell sorting system can be configured to sort the cell by directing the cell to a selected channel of the plurality of channels based on the analyzed image of the cell. The analyzed image may be indicative of one or more features of the cell, wherein the feature(s) are used as parameters of cell sorting. In some cases, one or more channels of the plurality of channels can have a plurality of sub-channels, and the plurality of sub-channels can be used to further sort the cells that have been sorted once.

In some aspects, the systems and methods disclosed herein use an active sorting mechanism. In various embodiments, the active sorting is independent from analysis and decision making platforms and methods. In various embodiments the sorting is performed by a sorter, which receives a signal from the decision making unit (e.g. a classifier), or any other external unit, and then sorts cells as they arrive at the bifurcation. The term bifurcation as used herein refers to the termination of the flow channel into two or more channels, such that cells with the one or more desired characteristics are sorted or directed towards one of the two or more channels and cell without the one or more desired characteristics are directed towards the remaining channels. In some embodiments, the flow channel terminates into 2, 3, 4, 5, 6, 7, 8, 9, 10 or more channels. In some embodiments, the flow channel terminates in two channels and cells with one or more desired characteristics are directed towards one of the two channels (the positive channel), while cells without the one or more desired characteristics are directed towards the other channel (the negative channel). In some embodiments, the flow channel terminates in three channels and cells with a first desired characteristic are directed to one of the three channels, cells with a second desired characteristic are directed to another of the three channels, and cells without the first desired characteristic and the second desired characteristic are directed to the remaining of the three channels.

In some embodiments, the sorting is performed by a sorter. The sorter may function by predicting the exact time at which the particle will arrive at the bifurcation. To predict the time of particle arrival, the sorter can use any applicable method. In some examples, said sorter predicts the time of arrival of the particle by using velocity of particles that are upstream and the distance between velocity calculation location and bifurcation. In some examples, said sorter predicts the time of arrival of the particles by using a constant delay time as an input.

In some examples, said sorter predicts the time of arrival of the particles by using a self-included unit which is capable of detecting the particle as it arrives at the bifurcation. In order to sort the particles, the order at which the particles arrive at the bifurcation, as detected by the self-included unit, is matched to the order of the received signal from the decision making unit (e.g. a classifier). In some aspects, controlled particles are used to align and update the order as necessary. In some aspects, said controlled particles are special calibration beads. In some embodiments the calibration beads used are polystyrene beads with size ranging between about 1 μM to about 50 μM. In some embodiments the calibration beads used are polystyrene beads with size of least about 1 μM. In some embodiments the calibration beads used are polystyrene beads with size of at most about 50 μM. In some embodiments the calibration beads used are polystyrene beads with size ranging between about 1 μM to about 3 μM, about 1 μM to about 5 μM, about 1 μM to about 6 μM, about 1 μM to about 10 μM, about 1 μM to about 15 μM, about 1 μM to about 20 μM, about 1 μM to about 25 μM, about 1 μM to about 30 μM, about 1 μM to about 35 μM, about 1 μM to about 40 μM, about 1 μM to about 50 μM, about 3 μM to about 5 μM, about 3 μM to about 6 μM, about 3 μM to about 10 μM, about 3 μM to about 15 μM, about 3 μM to about 20 μM, about 3 μM to about 25 μM, about 3 μM to about 30 μM, about 3 μM to about 35 μM, about 3 μM to about 40 μM, about 3 μM to about 50 μM, about 5 μM to about 6 μM, about 5 μM to about 10 μM, about 5 μM to about 15 μM, about 5 μM to about 20 μM, about 5 μM to about 25 μM, about 5 μM to about 30 μM, about 5 μM to about 35 μM, about 5 μM to about 40 μM, about 5 μM to about 50 μM, about 6 μM to about 10 μM, about 6 μM to about 15 μM, about 6 μM to about 20 μM, about 6 μM to about 25 μM, about 6 μM to about 30 μM, about 6 μM to about 35 μM, about 6 μM to about 40 μM, about 6 μM to about 50 μM, about 10 μM to about 15 μM, about 10 μM to about 20 μM, about 10 μM to about 25 μM, about 10 μM to about 30 μM, about 10 μM to about 35 μM, about 10 μM to about 40 μM, about 10 μM to about 50 μM, about 15 μM to about 20 μM, about 15 μM to about 25 μM, about 15 μM to about 30 μM, about 15 μM to about 35 μM, about 15 μM to about 40 μM, about 15 μM to about 50 μM, about 20 μM to about 25 μM, about 20 μM to about 30 μM, about 20 μM to about 35 μM, about 20 μM to about 40 μM, about 20 μM to about 50 μM, about 25 μM to about 30 μM, about 25 μM to about 35 μM, about 25 μM to about 40 μM, about 25 μM to about 50 μM, about 30 μM to about 35 μM, about 30 μM to about 40 μM, about 30 μM to about 50 μM, about 35 μM to about 40 μM, about 35 μM to about 50 μM, or about 40 μM to about 50 μM. In some embodiments the calibration beads used are polystyrene beads with size of about 1 μM, about 3 μM, about 5 μM, about 6 μM, about 10 μM, about 15 μM, about 20 μM, about 25 μM, about 30 μM, about 35 μM, about 40 μM, or about 50 μM.

In some embodiments, the sorters used in the systems and methods disclosed herein are self-learning cell sorting systems or intelligent cell sorting systems. These sorting systems can continuously learn based on the outcome of sorting. For example, a sample of cells is sorted, the sorted cells are analyzed, and the results of this analysis are fed back to the classifier.

In some aspects, the sorters used in the systems and methods disclosed herein do not rely on “supervised labels.” In some aspects, the sorters can identify “different looking” sub-populations in a sample, wherein said system automatically identifies and clusters different cell types, in the way of unsupervised learning or semi-supervised learning, by running and collecting their features, thus, by imaging them. In some aspects, said system works by running the sample for a few seconds, wherein the classifier then “learns” the components of the sample, then the actual sorting of those classes begins. In some aspects, said system is a sorter system where the sorting decision is made by artificial intelligence (AI), such as deep learning.

In some embodiments, the system and methods of the present disclosure comprise a cascaded sorting system, wherein a first step bulk sorting is carried out, wherein a subgroup of particles in a sample are monitored simultaneously for a positive particle (for example for a cell with one or more desired characteristics) and if any positive particle is detected in the subgroup of particles then, the subgroup of particles is subjected to further sorting. In some embodiments, the cascade sorting comprises capturing an image of a subgroup of a plurality of cells as said plurality of cells pass through a first flow channel; and analyzing said image for a feature. Following which, if said feature is detected then one or more cells in said subgroup are imaged again. In some embodiments, the first step comprises imaging 10 to 100 cells at a time and if any positive cell is detected, the group of 10 to 100 cells is sent to one side of the bifurcation and analyzed again. In some aspects, the first step comprises imaging 20 to 100 cells at a time. In some aspects, the first step comprises imaging 30 to 100 cells at a time. In some aspects, the first step comprises imaging 40 to 100 cells at a time. In some aspects, the first step comprises imaging 50 to 100 cells monitored at a time. In some aspects, the first step comprises imaging 50 to 100 cells at a time. In some aspects, the first step comprises imaging 60 to 100 cells at a time. In some aspects, the first step comprises imaging 70 to 100 cells at a time. In some aspects, the first step comprises imaging 80 to 100 cells at a time. In some aspects, the first step comprises imaging 90 to 100 cells at a time. In some aspects, the first step is followed by a next phase sorting of the subgroup of cells according to the methods described herein. In some embodiments, said next phase sorting is performed by directing the subgroup of cells to a second flow channel and by imaging the cells in the subgroup, single cell at a time according to the methods described herein.

Sorting Techniques

In some embodiments, the methods and systems disclosed herein can use any sorting technique to sort particles. An exemplary design for sorting the cells is shown in FIG. 11, wherein desired cell are directed to/sorted into the positive collection reservoir. In some embodiments, the sorting technique comprises closing a channel on one side of the bifurcation to collect the desired cell on the other side. In some aspects, the closing of the channels can be carried out by employing any known technique. In some aspects, said closing is carried out by application of a pressure. In some instances, said pressure is pneumatic actuation. In some aspects, said pressure can be positive pressure or negative pressure. In some embodiments, positive pressure is used. In some examples, one side of the bifurcation is closed by applying pressure and deflecting the soft membrane between top and bottom layers. Pneumatic actuation is further described in WO2001001025A2, which is incorporated herein by reference in its entirety.

In some aspects, said particles to be sorted are directed to one side of the bifurcation by increasing the fluidic resistance on the other side. For example, if one side of the bifurcation can be designed to have a longer channel compared to other side. In such embodiments, the cells normally go to the other (shorter) channel even when both valves are open. In such cases, the cells will go to the longer channel only when the valve on the shorter channel is closed.

In some embodiments, said closing of a channel on one side of the bifurcation is carried out by application of an electric filed. In some examples, said closing of a channel on one side of the bifurcation is achieved by using piezo actuator. For example, a piezo actuator can be used along to the channel. When a voltage is added to the piezo, the piezo deforms by elongating and/or pinching the channel cross section. A schematic representation of the use of piezo actuator is shown in FIG. 12. In some instances, a deformable material is used for the microfluidic channels, for example polydimethylsiloxane (PDMS) is used.

In some aspects, said closing of a channel on one side of the bifurcation is carried out by application of a magnetic field. In some examples, said closing of a channel on one side of the bifurcation is achieved by using magnetic actuation. For example, an electromagnet (EM) can be used along one side of the channel and a magnet can be used on the other side of the channel. In some instances, when the electromagnet is activated, said magnet becomes attracted to the electromagnet, leaving the channel cross-section to be pinched and closed. In some instances, a deformable material, for example is used for polydimethylsiloxane (PDMS) for the microfluidic channels shown in (FIG. 13).

Sample and Data Collection

In various embodiments, the systems and methods of the present disclosure comprise one or more reservoirs designed to collect the particles after the particles have been sorted. In some embodiments, the number of cells to be sorted is about 1 cell to about 1,000,000 cells. In some embodiments, the number of cells to be sorted is at least about 1 cell. In some embodiments, the number of cells to be sorted is at most about 1,000,000 cells. In some embodiments, the number of cells to be sorted is about 1 cell to about 100 cells, about 1 cell to about 500 cells, about 1 cell to about 1,000 cells, about 1 cell to about 5,000 cells, about 1 cell to about 10,000 cells, about 1 cell to about 50,000 cells, about 1 cell to about 100,000 cells, about 1 cell to about 500,000 cells, about 1 cell to about 1,000,000 cells, about 100 cells to about 500 cells, about 100 cells to about 1,000 cells, about 100 cells to about 5,000 cells, about 100 cells to about 10,000 cells, about 100 cells to about 50,000 cells, about 100 cells to about 100,000 cells, about 100 cells to about 500,000 cells, about 100 cells to about 1,000,000 cells, about 500 cells to about 1,000 cells, about 500 cells to about 5,000 cells, about 500 cells to about 10,000 cells, about 500 cells to about 50,000 cells, about 500 cells to about 100,000 cells, about 500 cells to about 500,000 cells, about 500 cells to about 1,000,000 cells, about 1,000 cells to about 5,000 cells, about 1,000 cells to about 10,000 cells, about 1,000 cells to about 50,000 cells, about 1,000 cells to about 100,000 cells, about 1,000 cells to about 500,000 cells, about 1,000 cells to about 1,000,000 cells, about 5,000 cells to about 10,000 cells, about 5,000 cells to about 50,000 cells, about 5,000 cells to about 100,000 cells, about 5,000 cells to about 500,000 cells, about 5,000 cells to about 1,000,000 cells, about 10,000 cells to about 50,000 cells, about 10,000 cells to about 100,000 cells, about 10,000 cells to about 500,000 cells, about 10,000 cells to about 1,000,000 cells, about 50,000 cells to about 100,000 cells, about 50,000 cells to about 500,000 cells, about 50,000 cells to about 1,000,000 cells, about 100,000 cells to about 500,000 cells, about 100,000 cells to about 1,000,000 cells, or about 500,000 cells to about 1,000,000 cells. In some embodiments, the number of cells to be sorted is about 1 cell, about 100 cells, about 500 cells, about 1,000 cells, about 5,000 cells, about 10,000 cells, about 50,000 cells, about 100,000 cells, about 500,000 cells, or about 1,000,000 cells.

In some embodiments, the number of cells to be sorted is 100 to 500 cells, 200 to 500 cells, 300 to 500 cells, 350 to 500 cells, 400 to 500 cells, or 450 to 500 cells. In some embodiments, said reservoirs may be milliliter scale reservoirs. In some examples, the one or more reservoirs are pre-filled with a buffer and the sorted cells are stored in the buffer. Using the buffer helps to increase the volume of the cells, which can then be easily handled, for example a pipetted. In some examples, the buffer is a phosphate buffer, for example phosphate-buffered saline (PBS).

In some embodiments, the system and methods of the present disclosure comprise a cell sorting technique wherein pockets of buffer solution containing no negative objects are sent to the positive output channel in order to push rare objects out of the collection reservoir. In some aspects, additional buffer solution is sent to said positive output channel to flush out all positive objects at the end of a run, once the channel is flushed clean.

Real-Time Integration

In some embodiments, the system and methods of the present disclosure comprise a combination of techniques, wherein a graphics processing unit (GPU) and a digital signal processor (DSP) are used to run artificial intelligence (AI) algorithms and apply classification results in real-time to the system. In some aspects, the system and methods of the present disclosure comprise a hybrid method for real-time cell sorting.

Validation

In some embodiments, the systems disclosed herein further comprise a validation unit that detects the presence of a particle without getting detailed information, such as imaging. In some instances, said validation unit may be used for one or more purposes. For e.g. in some examples, said validation unit detects a particle approaching the bifurcation and enables precise sorting. In some examples, said validation unit provides timing information with two laser spots. In some instances, said validation unit provides timing information by referencing the imaging time. In some instances, said validation unit provides precise time delay information and/or flow speed of particles.

In some embodiments, said validation unit is a laser-assisted system. In some aspects, said laser-assisted system measures the laser blockage or scattering, and thereby the size of the particle may be inferred. In some aspects, said laser-assisted system measures the laser blockage scattering, and thereby other physical information of the particle may be inferred, including but not limited to the size, the shape, the density, and the texture. In some aspects, said laser-assisted system measures the laser blockage or scattering, and thereby the transient speed of the object may be inferred.

In some embodiments, the validation unit, for e.g. the laser-assisted system, is located after the bifurcation (for e.g. on the positive side, on the negative side, or on both sides). In some examples, such a location of the validation unit provides clarification information on the accuracy and effectiveness of the sorting. In some aspects, the validation system may be used to create a closed feedback loop to adjust the control parameters of the system. In some instances, said closed feedback loop can be used to improve system accuracy and/or to accommodate slow system draft over the course of the experimental run.

In some embodiments, the validation unit comprises a laser-assisted system wherein two or more laser spots are utilized. When the two or more laser spots are closely placed, different methods, disclosed herein, are used to create said the two or more laser spots and later separate into two or more independent signals for photo detection. In some embodiments, the distance between the two or more closely spaced laser spots is in the range of 10 μm-about 1,000 μm, for example said distance is between 10 μm to 500 μm, between 50 μm to 500 μm, 100 μm to 500 μm, 150 μm to 500 μm, between 200 μm to 500 μm, between 250 μm to 500 μm, between 300 μm to 500 μm, between 350 μm to 500 μm, between 400 μm to 500 μm, or between 450 μm to 500 μm.

In some embodiments, said two or more closely spaced laser spots come from different optical trains with their respective tilt angle. In some aspects, said two or more closely spaced lasers pass through the same focusing optics but come in with slightly different angles and thus, get focused with slight offset to each other. In some aspects, said two or more closely spaced laser spots have different wavelengths and are recombined with slight offset through a dichroic mirror that passes some lasers while reflecting the other lasers, wherein with the proper arrangement, said lasers can come out together with the desired offset. In some aspects, said two or more lasers spots have different polarizations and can be recombined with a desired offset through a polarization beam splitter. In some aspects, said two or more closely spaced lasers are generated by recombining with a close proximity through a general purpose beam-splitter as shown in FIG. 14.

In some embodiments, the signals from the two or more closely spaced lasers can be separated by reversing the creation methods described herein. In some aspects, the signals of the two or more lasers can be separated using optical components with a good alignment. In some instances, said optical component is a round glass ball. In some aspects, the signals of the two or more lasers can be separated by sending the signal to a position-sensitive detector. In some instances, said position-sensitive detector is a dual photodetector. In some instances, said position-sensitive detector is a quad photodetector. In some aspects, the present disclosure comprises a laser-assisted system wherein two closely spaced laser spots are utilized. In some aspects, said laser spots comprise a slit in between, wherein the change in different detection area is used to calculate the original two laser signal changes.

In some embodiments, the validation of particle sorting by the methods and the system disclosed herein is performed by the using the back channel design as shown in FIG. 15. In these embodiments, the validation comprises imaging both the flow channel where the cells are imaged for the first time, known as the forward channel, and the outlet, where the cells flow after being sorted. In some aspects, the outlet is designed as a backchannel that fits in the same field of view as the imaging device used to image the particles in the flow channel. In some aspects, the outlet particles can be identified against the forward channel particles by their location and/or velocity. In some instances, the velocity of the particles is positive in the forward channel. In some instances, the velocity of the particles is negative in the backward channel.

Samples

In some embodiments, the particles (for e.g. cells) analyzed by the systems and methods disclosed herein are comprised in a sample. The sample may be a biological sample obtained from a subject. In some embodiments, the biological sample comprises a biopsy sample from a subject. In some embodiments, the biological sample comprises a tissue sample from a subject. In some embodiments, the biological sample comprises liquid biopsy from a subject. In some embodiments, the biological sample can be a solid biological sample, e.g., a tumor sample. In some embodiments, a sample from a subject can comprise at least about 1%, at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or at least about 100% tumor cells from a tumor.

In some embodiments, the sample can be a liquid biological sample. In some embodiments, the liquid biological sample can be a blood sample (e.g., whole blood, plasma, or serum). A whole blood sample can be subjected to separation of cellular components (e.g., plasma, serum) and cellular components by use of a Ficoll reagent. In some embodiments, the liquid biological sample can be a urine sample. In some embodiments, the liquid biological sample can be a perilymph sample. In some embodiments, the liquid biological sample can be a fecal sample. In some embodiments, the liquid biological sample can be saliva. In some embodiments, the liquid biological sample can be semen. In some embodiments, the liquid biological sample can be amniotic fluid. In some embodiments, the liquid biological sample can be cerebrospinal fluid. In some embodiments, the liquid biological sample can be bile. In some embodiments, the liquid biological sample can be sweat. In some embodiments, the liquid biological sample can be tears. In some embodiments, the liquid biological sample can be sputum. In some embodiments, the liquid biological sample can be synovial fluid. In some embodiments, the liquid biological sample can be vomit.

In some embodiments, samples can be collected over a period of time and the samples may be compared to each other or with a standard sample using the systems and methods disclosed herein. In some embodiments the standard sample is a comparable sample obtained from a different subject, for example a different subject that is known to be healthy or a different subject that is known to be unhealthy. Samples can be collected over regular time intervals, or can be collected intermittently over irregular time intervals.

In some embodiments, the subject may be an animal (e.g., human, rat, pig, horse, cow, dog, mouse). In some instances, the subject is a human and the sample is a human sample. The sample may be a fetal human sample. The sample may be from a multicellular tissue (e.g., an organ (e.g., brain, liver, lung, kidney, prostate, ovary, spleen, lymph node, thyroid, pancreas, heart, skeletal muscle, intestine, larynx, esophagus, and stomach), a blastocyst). The sample may be a cell from a cell culture. In some sample the subject is a pregnant human, or a human suspected to be pregnant.

The sample may comprise a plurality of cells. The sample may comprise a plurality of the same type of cell. The sample may comprise a plurality of different types of cells. The sample may comprise a plurality of cells at the same point in the cell cycle and/or differentiation pathway. The sample may comprise a plurality of cells at different points in the cell cycle and/or differentiation pathway.

The plurality of samples may comprise one or more malignant cell. The one or more malignant cells may be derived from a tumor, sarcoma, or leukemia.

The plurality of samples may comprise at least one bodily fluid. The bodily fluid may comprise blood, urine, lymphatic fluid, saliva. The plurality of samples may comprise at least one blood sample.

The plurality of samples may comprise at least one cell from one or more biological tissues. The one or more biological tissues may be a bone, heart, thymus, artery, blood vessel, lung, muscle, stomach, intestine, liver, pancreas, spleen, kidney, gall bladder, thyroid gland, adrenal gland, mammary gland, ovary, prostate gland, testicle, skin, adipose, eye or brain.

The biological tissue may comprise an infected tissue, diseased tissue, malignant tissue, calcified tissue or healthy tissue.

Non-Invasive Prenatal Testing (NIPT)

Conventional prenatal screening methods for detecting fetal abnormalities and for sex determination use fetal samples acquired through invasive techniques, such as amniocentesis and chorionic villus sampling (CVS). Ultrasound imaging is also used to detect structural malformations such as those involving the neural tube, heart, kidney, limbs and the like. Chromosomal aberrations such as the presence of extra chromosomes, such as Trisomy 21 (Down syndrome), Klinefelter's syndrome, Trisomy 13 (Patau syndrome), Trisomy 18 (Edwards syndrome), or the absence of chromosomes, such as Turner's syndrome, or various translocations and deletions can be currently detected using CVS and/or amniocentesis. Both techniques require careful handling and present a degree of risk to the mother and to the pregnancy.

Prenatal diagnosis is offered to women over the age of 35 and/or women who are known to carry genetic diseases, as balanced translocations or microdeletions.

Chorionic villus sampling (CVS) is performed between the 9^(th) and the 14^(th) week of gestation. CVS involves the insertion of a catheter through the cervix or the insertion of a needle into the abdomen of the subject/patient. The needle or catheter is used to remove a small sample of the placenta, known as the chorionic villus. The fetal karyotype is then determined within one to two weeks of the CVS procedure. Due to the invasive nature of the CVS procedure, there is a 2 to 4% procedure-related risk of miscarriage. CVS is also associated with an increased risk of fetal abnormalities, such as defective limb development, which are presumably due to hemorrhage or embolism from the aspirated placental tissues.

Amniocentesis is performed between the 16^(th) and the 20^(th) week of gestation. Amniocentesis involves the insertion of a thin needle through the abdomen into the uterus of the patient. This procedure carries a 0.5 to 1% procedure-related risk of miscarriage. Amniotic fluid is aspirated by the needle and fetal fibroblast cells are further cultured for 1 to 2 weeks, following which they are subjected to cytogenetic and/or fluorescence in situ hybridization (FISH) analyses.

Recent techniques have been developed to predict fetal abnormalities and predict possible complications in pregnancy. These techniques use material blood or serum samples and have focused on the use of three specific markers, including alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), and estriol. These three markers are used to screen for Down's syndrome and neural tube defects. Maternal serum is currently being used for biochemical screening for chromosomal aneuploidies and neural tube defects.

The passage of nucleated cells between the mother and fetus is a well-studied phenomenon. Using the fetal cells that are present in maternal blood for non-invasive prenatal diagnosis prevents the risks that are usually associated with conventional invasive techniques. Fetal cells include fetal trophoblasts, leukocytes, and nucleated erythrocytes from the maternal blood during the first trimester of pregnancy. This said, the isolation of trophoblasts from the maternal blood is limited by their multinucleated morphology and the availability of antibodies, whereas the isolation of leukocytes is limited by the lack of unique cell markers which differentiate maternal from fetal leukocytes. Furthermore, since leukocytes may persist in the maternal blood for as long as 27 years, residual cells are likely to be present in the maternal blood from previous pregnancies.

In some embodiments, the system and methods disclosed herein are used for non-invasive prenatal testing (NIPT), wherein said methods are used to analyze maternal serum or plasma samples from a pregnant female. In some aspects, said system and methods are used for non-invasive prenatal diagnosis. In some aspects, the system and methods disclosed herein can be used to analyze maternal serum or plasma samples derived from maternal blood. In some aspects, as little as 10 μL of serum or plasma can be used. In some aspects, larger samples are used to increase accuracy, wherein the volume of the sample used is dependent upon the condition or characteristic being detected.

In some embodiments, the system and methods disclosed herein are used for non-invasive prenatal diagnosis including but not limited to sex determination, blood typing and other genotyping, detection of pre-eclampsia in the mother, determination of any maternal or fetal condition or characteristic related to either the fetal DNA itself or the quantity or quality of the fetal DNA in the maternal serum or plasma, and identification of major or minor fetal malformations or genetic diseases present in a fetus. In some aspects, fetus is a human fetus.

In some embodiments, the system and methods disclosed herein are used to analyze serum or plasma from maternal blood samples, wherein said serum or plasma preparation is carried out by standard techniques and subjected to a nucleic acid extraction process. In some aspects, said serum or plasma is extracted using a proteinase K treatment followed by phenol/chloroform extraction.

In some embodiments, the system and methods disclosed herein are used to image cells from maternal serum or plasma acquired from a pregnant female subject. In some aspects, said subject is a human. In some aspects, said pregnant female human subject is over the age of 35. In some aspects, said pregnant female human subject is known to carry a genetic disease. In some aspects, said subject is a human. In some aspects, said pregnant female human subject is over the age of 35 and is known to carry a genetic disease.

In some embodiments, the system and methods disclosed herein are used to analyze fetal cells from maternal serum or plasma. In some aspects, the cells that are used for non-invasive prenatal testing using the system and methods disclosed herein are fetal cells such as fetal trophoblasts, leukocytes, and nucleated erythrocytes. In some aspects, fetal cells are from the maternal blood during the first trimester of pregnancy.

In some embodiments, the system and methods disclosed herein are used for non-invasive prenatal diagnosis using fetal cells comprising trophoblast cells. In some aspects, trophoblast cells using the present disclosure are retrieved from the cervical canal using aspiration. In some aspects, trophoblast cells using the present disclosure are retrieved from the cervical canal using cytobrush or cotton wool swabs. In some aspects, trophoblast cells using the present disclosure are retrieved from the cervical canal using endocervical lavage. In some aspects, trophoblast cells using the present disclosure are retrieved from the cervical canal using intrauterine lavage.

In some embodiments, the system and methods disclosed herein are used to analyze fetal cells from maternal serum or plasma, wherein the cell population is mixed and comprises fetal cells and maternal cells. In some aspects, the system and methods of the present disclosure are used to identify embryonic or fetal cells in a mixed cell population. In some embodiments, the system and methods of the present disclosure are used to identify embryonic or fetal cells in a mixed cell population, wherein nuclear size and shape are used to identify embryonic or fetal cells in a mixed population. In some embodiments, the systems and methods disclosed herein are used to sort fetal cells from a cell population.

In some embodiments, the system and methods disclosed herein are used to measure the count of fetal nucleated red blood cells (RBCs), wherein an increase in fetal nucleated RBC count indicates the presence of fetal aneuploidy.

In some embodiments, the system and methods disclosed herein are used to image cells from maternal serum or plasma acquired from a pregnant female subject. In some aspects, said cells are not labelled. In some aspects, said cells are in a flow. In some aspects, said cells are imaged from different angles. In some aspects, said cells are live cells. In some aspects, said cells are housed in a flow channel within the system of the present disclosure, wherein the flow channel has walls formed to space the plurality of cells within a single streamline. In some aspects, said cells are housed in a flow channel within the system of the present disclosure, wherein the flow channel has walls formed to rotate the plurality of said cells within a single streamline.

In some embodiments, the system and methods disclosed herein are used to image cells from maternal serum or plasma acquired from a pregnant female subject. In some aspects, a plurality of images of said cells is collected using the system and methods of the present disclosure. In some aspects, the plurality of images is analyzed to determine if specific disease conditions are present in the subject, wherein said cells are in a flow during the imaging and wherein the plurality of images comprises images of said cells from a plurality of angles. In some aspects, subject is the fetus. In some aspects, subject is pregnant female subject.

Sperm Analysis

In some embodiments, the sample used in the methods and systems described herein is a semen sample, and the system and methods of the present disclosure are used to identify sperm quality and/or gender. In these embodiments, the methods described herein comprise imaging the semen sample from the subject according to the methods described herein and analyzing the sperms in the semen sample for one or more features. In some embodiments, the systems and methods described herein are used to obtain a sperm count. In some aspects, the systems and methods described herein are used to obtain information about sperm viability and/or health. In some aspects, the systems and methods described herein are used to obtain information about sperm gender. In some embodiments, the sorting systems and methods described herein are used for and automated enrichment of sperms with desired morphological features. In some embodiment, the enriched sperms obtained according to the methods and systems described herein are used for in-vitro fertilization. In some aspects, said features are associated with health, motility, and/or gender.

Cancer Cells

Many cancers are diagnosed in later stages of the disease because of low sensitivity of existing diagnostic procedures and processes. More than 1.5 million people are diagnosed with cancer every year in the USA, of which 600,000 people die (Jemal et al. 2010). Currently, the first cancer screening procedure involves the detection of a tumor. Many cancer tumors, such as breast cancer are detected by self- or clinical examination. However, these tumors are typically detected only after the tumor reach a volume of 1 mL or 1 cc, when it contains approximately 10⁹ cells. Routine screening by mammography is more sensitive and allows detection of a tumor before it becomes palpable, but only after they reach an inch in diameter. MRI, positron emission tomography (PET) and single-photon emission computed tomography (SPECT) can reveal even smaller tumors than can be detected by mammograms. However, these imaging methods present significant disadvantages. Contrast agents for magnetic resonance imaging (MRI) are toxic and radionuclides delivered for SPECT or PET examination are sources of ionizing radiation. Because of its relatively poor resolution, ovarian cancer often requires several follow up scans with computed tomography (CT) or MRI, while undertaking all precautions to protect possible pregnancies, to reveal fine anatomy of developing tumors (Shin et al. 2011). Additionally, all of these diagnostic techniques require dedicated facilities, expensive equipment, well trained staff, and financial coverages.

Cancer is commonly diagnosed in patients by obtaining a sample of the suspect tissue and examining said tissue under a microscope for the presence of malignant cells. While this process is relatively straightforward when the anatomic location of the suspect tissue is known, it can become quite challenging when there is no readily identifiable tumor or pre-cancerous lesion. For example, to detect the presence of lung cancer from a sputum sample requires one or more relatively rare cancer cells to be present in the sample. Therefore, patients having lung cancer may not be diagnosed properly if the sample does not perceptively and accurately reflect the conditions of the lung.

Conventional light microscopy, which utilizes cells mounted on glass slides, can only approximate 2D and 3D measurements because of limitations in focal plane depth, sampling angles, and problems with cell preparations that typically cause cells to overlap in the plane of the image. Another drawback of light microscopy is the inherent limitation of viewing through an objective lens where only the area within the narrow focal plane provides accurate data for analysis.

Flow cytometry methods generally overcome the cell overlap problem by causing cells to flow one-by-one in a fluid stream. Unfortunately, flow cytometry systems do not generate images of cells of the same quality as traditional light microscopy, and, in any case, the images are not three-dimensional.

In some embodiments, the system and methods disclosed herein enable the acquisition of three-dimensional imaging data of individual cells, wherein each individual cell from a cell population is imaged from a plurality of angles. In some aspects, the present disclosure is used to diagnose cancer, wherein individual cancer cells are identified, tracked, and grouped together. In some aspects, said cells are live.

In some embodiments, the system and methods disclosed herein are used for cancer diagnosis in a subject, the method comprising imaging a cell in a biological sample from the subject to collect a plurality of images of the cell and analyzing the plurality of images to determine if cancerous cells are present in the subject, wherein the cancerous cell is in a flow during imaging and is spinning, and wherein the plurality of images comprise images from a different spinning angles.

In some embodiments, the system and methods disclosed herein are used for cancer cell detection, wherein the cancerous cells are from biological samples and are detected and tracked as they pass through the system of the present disclosure.

In some embodiments, the system and methods disclosed herein are used to identify cancer cells from biological samples acquired from mammalian subjects, wherein the cell population is analyzed by nuclear detail, nuclear contour, presence or absence of nucleoli, quality of cytoplasm, quantity of cytoplasm, nuclear aspect ratio, cytoplasmic aspect ratio, or nuclear to cytoplasmic ratio. In some aspects, the cancer cells that are identified indicate the presence of cancer in the mammalian sample, including but not limited to, lymphoma, myeloma, neuroblastoma, breast cancer, ovarian cancer, lung cancer, rhabdomyosarcoma, small-cell lung tumors, primary brain tumors, stomach cancer, colon cancer, pancreatic cancer, urinary bladder cancer, testicular cancer, lymphomas, thyroid cancer, neuroblastoma, esophageal cancer, genitourinary tract cancer, cervical cancer, endometrial cancer, adrenal cortical cancer, or prostate cancer. In some aspects, the said cancer is metastatic cancer. In some aspects, the said cancer is an early stage cancer.

In some embodiments, the system and methods disclosed herein are used to image a large number of cells from a subject and collect a plurality of images of the cell, and to then classify the cells based on an analysis of one or more of the plurality of images; wherein the plurality of images comprise images from a plurality of cell angles and wherein the cell is tracked until the cell has been classified. In some aspects, the tracked cells are classified as cancerous. In some aspects, the subject is a human.

In some embodiments, the cells used in the methods disclosed herein are live cells. In some aspects, the cells that are classified as cancerous cells are isolated and subsequently cultured for potential drug compound screening, testing of a biologically active molecule, and/or further studies.

In some embodiments, the system and methods disclosed herein are used to identify cancer cells from a cell population from a mammalian subject. In some aspects, said subject is a human. In some aspects, the system and methods disclosed herein are used to determine the progression of a cancer, wherein samples from a subject are obtained from two different time points and compared using the methods of the present disclosure. In some aspects, the system and methods disclosed herein are used to determine the effectiveness of an anti-cancer treatment, wherein samples from a subject are obtained before and after anti-cancer treatment and comparing the two samples using the methods of the present disclosure.

In some embodiments, the system and methods disclosed herein comprise a cancer detection system that uses a rapidly trained neural network, wherein said neural network detects cancerous cells by analyzing raw images of the cell and provides imaging information from the pixels of the images to a neural network. In some aspects, said neural network performs recognition and identification of cancerous cells using information derived from an image of the cells, among others, the area, the average intensity, the shape, the texture, and the DNA (pgDNA) of the cells. In some aspects, said neural network performs recognition of cancerous cells using textural information derived from an image of the cells, among them angular second moment, contrast, coefficient of correlation, sum of squares, difference moment, inverse difference moment, sum average, sum variance, sum entropy, entry, difference variance, difference entropy, information measures, maximal correlation coefficient, coefficient of variation, peak transition probability, diagonal variance, diagonal moment, second diagonal moment, product moment, triangular symmetry and blobness.

Bacteria from Human Cells

In some embodiments, the methods disclosed herein are used for bacterial detection, wherein the human cells containing bacteria are from biological samples and are detected and tracked as they pass through the system of the present disclosure.

In some embodiments, the system and methods disclosed herein enable the acquisition of three-dimensional imaging data of bacteria present in a sample, wherein each individual bacterium is imaged from a plurality of angles. In some embodiments, the system and methods disclosed herein are used for bacterial detection, wherein the bacteria is from biological samples and are detected and tracked as they pass through the system of the present disclosure.

In some embodiments, the system and methods disclosed herein are used to detect bacteria in fluids, including blood, platelets, and other blood products for transfusion, and urine. In some aspects, the present disclosure provides a method for separating intact eukaryotic cells from suspected intact bacterial cells that may be present in the fluid sample. In some aspects, the present disclosure identifies certain bacterial species, including but not limited to: Bacillus cereus, Bacillus subtilis, Clostridium perfringens, Corynebacterium species, Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, Propionibacterium acnes, Pseudomonas aeruginosa, Salmonella choleraesuis, Serratia marcesens, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, and Streptococcus viridans.

In some embodiments, the system and methods disclosed herein comprise a bacterial detection system that uses a rapidly trained neural network, wherein said neural network detects bacteria by analyzing raw images of the cell and provides imaging information from the pixels of the images to a neural network. In some aspects, said neural network performs recognition and identification of bacteria using information derived from an image of the bacteria, among others, the area, the average intensity, the shape, the texture, and the DNA (pgDNA) of the cells. In some aspects, said neural network performs recognition of cancerous cells using textural information derived from an image of the cells, among them angular second moment, contrast, coefficient of correlation, sum of squares, difference moment, inverse difference moment, sum average, sum variance, sum entropy, entry, difference variance, difference entropy, information measures, maximal correlation coefficient, coefficient of variation, peak transition probability, diagonal variance, diagonal moment, second diagonal moment, product moment, triangular symmetry and blobness.

Sickle Cell Disease

In some embodiments, the system and methods disclosed herein are used for the detection and/or identification of a sickle cell. In some aspects, the system and methods disclosed herein are used to image a cell and to determine if the cell is a sickle cell. The methods of the disclosure may be further used to collect the cells determined to be sickle cells. In some embodiments the cell is from a biological sample from a subject and the methods disclosed herein are used to determine whether the subject suffers from or is susceptible to a sickle cell disease. In some embodiments, the sickle cell disease is a sickle cell anemia.

Crystals in Biological Samples

Current diagnostic methods used to detect crystals in blood and/or urine includes radiological, serological, sonographic, and enzymatic methods.

Urine crystals may be of several different types. Most commonly crystals are formed of struvite (magnesium-ammonium-phosphate), oxalate, urate, cysteine, or silicate, but may also be composed of other materials such as bilirubin, calcium carbonate, or calcium phosphate.

In some embodiments, the system and methods disclosed herein are used for the detection of crystals in biological samples. In some aspects, detected crystals are formed. In some aspects, said biological sample from a subject is imaged according to the methods described herein to determine whether the biological sample comprises a crystal. In some aspects, said biological sample is blood. In some aspects, said blood is venous blood of a subject. In some aspects, said biological sample is urine. In some aspects, said subject is a human, horse, rabbit, guinea pig, or goat. In some aspects, the methods of the disclosure may be further utilized to isolate and collect the crystal from the sample. In some aspects, said biological sample is from a subject and the system and methods of the present disclosure are used to determine whether the subject suffers from or is susceptible to disease or a condition.

In some embodiments, the methods disclosed herein are used for the analysis of a crystal from a biological sample. In some aspects, the methods disclosed herein may be used to image a crystal, and the crystal images may be analyzed for, including but not limited to, crystal shape, size, texture, morphology, and color. In some embodiments, the biological sample is from a subject and the methods disclosed herein are used to determine whether the subject suffers from a disease or a condition. In some example the subject is a human. For example, the methods of the disclosure may be used to analyze crystal in a blood sample of the human subject, and the results may be used to determine whether the subject suffers from pathological conditions, including but not limited to, chronic or rheumatic leukemia. In some aspects, said biological sample is a urine sample.

In some embodiments, the system and methods disclosed herein enable the acquisition of three-dimensional imaging data of crystals, if found in the biological sample, wherein each individual crystal is imaged from a plurality of angles.

In some embodiments, the system and methods disclosed herein comprise a crystal detection system that uses a rapidly trained neural network, wherein said neural network detects crystals by analyzing raw images of a plurality of crystals and provides imaging information from the pixels of the images to a neural network. In some aspects, said neural network performs recognition and identification of a plurality of crystals using information derived from an image of the crystals, among others, the area, the average intensity, the shape, the texture. In some aspects, said neural network performs recognition of crystals using textural information derived from an image of the cells, among them angular second moment, contrast, coefficient of correlation, sum of squares, difference moment, inverse difference moment, sum average, sum variance, sum entropy, entry, difference variance, difference entropy, information measures, maximal correlation coefficient, coefficient of variation, peak transition probability, diagonal variance, diagonal moment, second diagonal moment, product moment, triangular symmetry and blobness.

Liquid Biopsy

A liquid biopsy comprises the collection of blood and/or urine from a cancer patient with primary or recurrent disease and the analysis of cancer-associated biomarkers in the blood and/or urine. A liquid biopsy is a simple and non-invasive alternative to surgical biopsies that enables doctors to discover a range of information about a tumor. Liquid biopsies are increasingly being recognized as a viable, noninvasive method of monitoring a patient's disease progression, regression, recurrence, and/or response to treatment.

In some embodiments, the methods disclosed herein are used for liquid biopsy diagnostics, wherein the biopsy is a liquid biological sample that is passed through the system of the present disclosure. In some aspects, the liquid biological sample that is used for the liquid biopsy is less than 5 mL of liquid. In some aspects, the liquid biological sample that is used for the liquid biopsy is less than 4 mL of liquid. In some aspects, the liquid biological sample that is used for the liquid biopsy is less than 3 mL of liquid. In some aspects, the liquid biological sample that is used for the liquid biopsy is less than 2 mL of liquid. In some aspects, the liquid biological sample that is used for the liquid biopsy is less than 1 mL of liquid. In some aspects, the liquid biological sample that is used for liquid biopsy is centrifuged to get plasma.

In some embodiments, the system and methods of the present disclosure are used for body fluid sample assessment, wherein cells within a sample are imaged and analyzed and a report is generated comprising all the components within the sample, the existence of abnormalities in said sample, and a comparison to previously imaged or tested samples from the same patient or the baseline of other healthy individuals.

In some embodiments, the system and methods of the present disclosure are used for the diagnosis of immune diseases, including but not limited to tuberculosis (TB) and acquired immune deficiency disorder (AIDS), wherein white blood cells are imaged in the system disclosed herein to examine their capacity to release pro- and anti-inflammatory cytokines.

In some embodiments, the system and methods of the present disclosure are used to assess patient immune responses to immunomodulatory therapies by imaging their white blood cells and analyzing the change in their capacity to release pro- and anti-inflammatory cytokines.

In some embodiments, the system and methods of the present disclosure are used to identify the efficacy of therapeutics and/or to guide the selection of agents or their dosage by isolating patients' white blood cells and analyzing the effect of target therapeutics on their capacity to release pro- and anti-inflammatory cytokines.

In some embodiments, the system and methods of the present disclosure are used to isolate pure samples of stem cell-derived tissue cells by obtaining images of cells, and isolating cells with desired phenotype.

Testing Biologically Active Molecules

In some embodiments, the methods disclosed herein are used for biologically active molecule testing, for example drugs. In some embodiments, the methods of the disclosure are sued to collect desired cells from a sample and then treating the desired cells with a biologically active molecule in order to test the effect of the biologically active molecule on the collected cells.

In some embodiments, the methods and systems of the present disclosure are used for identifying the efficacy of therapeutics. In some aspects, identifying the efficacy of therapeutics using the system disclosed herein is carried out by obtaining images of a cell before and after treatment and analyzing the images to determine whether said cell has responded to the therapeutic of interest.

In some embodiments, the system and methods disclosed herein are used for diseased cell detection, wherein the diseased cells are from biological samples and are detected and tracked as they pass through the system of the present disclosure. In some aspects, said diseased cells are isolated and grouped together for further studies.

In some embodiments, the cells used in the methods disclosed herein are live cells. In some aspects, the cells that are classified as diseased cells are isolated and subsequently cultured for potential drug compound screening, testing of a biologically active molecule, and/or further studies.

Although the present disclosure has been described in certain specific aspects, many additional modifications and variations would be apparent to those skilled in the art. It is therefore to be understood that the present disclosure can be practiced otherwise than specifically described without departing from the scope and spirit of the present disclosure. Thus, some embodiments of the present disclosure should be considered in all respects as illustrative and not restrictive.

Computer Systems

The present disclosure provides computer systems that are programmed to implement methods of the disclosure. FIG. 16 shows a computer system 1601 that is programmed or otherwise configured to capture and/or analyze one or more images of the cell. The computer system 1601 can regulate various aspects of components of the cell sorting system of the present disclosure, such as, for example, the pump, the valve, and the imaging device. The computer system 1601 can be an electronic device of a user or a computer system that is remotely located with respect to the electronic device. The electronic device can be a mobile electronic device.

The computer system 1601 includes a central processing unit (CPU, also “processor” and “computer processor” herein) 1605, which can be a single core or multi core processor, or a plurality of processors for parallel processing. The computer system 1601 also includes memory or memory location 1610 (e.g., random-access memory, read-only memory, flash memory), electronic storage unit 1615 (e.g., hard disk), communication interface 1620 (e.g., network adapter) for communicating with one or more other systems, and peripheral devices 1625, such as cache, other memory, data storage and/or electronic display adapters. The memory 1610, storage unit 1615, interface 1620 and peripheral devices 1625 are in communication with the CPU 1605 through a communication bus (solid lines), such as a motherboard. The storage unit 1615 can be a data storage unit (or data repository) for storing data. The computer system 1601 can be operatively coupled to a computer network (“network”) 1630 with the aid of the communication interface 1620. The network 1630 can be the Internet, an internet and/or extranet, or an intranet and/or extranet that is in communication with the Internet. The network 1630 in some cases is a telecommunication and/or data network. The network 1630 can include one or more computer servers, which can enable distributed computing, such as cloud computing. The network 1630, in some cases with the aid of the computer system 1601, can implement a peer-to-peer network, which may enable devices coupled to the computer system 1601 to behave as a client or a server.

The CPU 1605 can execute a sequence of machine-readable instructions, which can be embodied in a program or software. The instructions may be stored in a memory location, such as the memory 1610. The instructions can be directed to the CPU 1605, which can subsequently program or otherwise configure the CPU 1605 to implement methods of the present disclosure. Examples of operations performed by the CPU 1605 can include fetch, decode, execute, and writeback.

The CPU 1605 can be part of a circuit, such as an integrated circuit. One or more other components of the system 1601 can be included in the circuit. In some cases, the circuit is an application specific integrated circuit (ASIC).

The storage unit 1615 can store files, such as drivers, libraries and saved programs. The storage unit 1615 can store user data, e.g., user preferences and user programs. The computer system 1601 in some cases can include one or more additional data storage units that are external to the computer system 1601, such as located on a remote server that is in communication with the computer system 1601 through an intranet or the Internet.

The computer system 1601 can communicate with one or more remote computer systems through the network 1630. For instance, the computer system 1601 can communicate with a remote computer system of a user. Examples of remote computer systems include personal computers (e.g., portable PC), slate or tablet PC's (e.g., Apple® iPad, Samsung® Galaxy Tab), telephones, Smart phones (e.g., Apple® iPhone, Android-enabled device, Blackberry®), or personal digital assistants. The user can access the computer system 1601 via the network 1630.

Methods as described herein can be implemented by way of machine (e.g., computer processor) executable code stored on an electronic storage location of the computer system 1601, such as, for example, on the memory 1610 or electronic storage unit 1615. The machine executable or machine readable code can be provided in the form of software. During use, the code can be executed by the processor 1605. In some cases, the code can be retrieved from the storage unit 1615 and stored on the memory 1610 for ready access by the processor 1605. In some situations, the electronic storage unit 1615 can be precluded, and machine-executable instructions are stored on memory 1610.

The code can be pre-compiled and configured for use with a machine having a processer adapted to execute the code, or can be compiled during runtime. The code can be supplied in a programming language that can be selected to enable the code to execute in a pre-compiled or as-compiled fashion.

Aspects of the systems and methods provided herein, such as the computer system 1601, can be embodied in programming. Various aspects of the technology may be thought of as “products” or “articles of manufacture” typically in the form of machine (or processor) executable code and/or associated data that is carried on or embodied in a type of machine readable medium. Machine-executable code can be stored on an electronic storage unit, such as memory (e.g., read-only memory, random-access memory, flash memory) or a hard disk. “Storage” type media can include any or all of the tangible memory of the computers, processors or the like, or associated modules thereof, such as various semiconductor memories, tape drives, disk drives and the like, which may provide non-transitory storage at any time for the software programming. All or portions of the software may at times be communicated through the Internet or various other telecommunication networks. Such communications, for example, may enable loading of the software from one computer or processor into another, for example, from a management server or host computer into the computer platform of an application server. Thus, another type of media that may bear the software elements includes optical, electrical and electromagnetic waves, such as used across physical interfaces between local devices, through wired and optical landline networks and over various air-links. The physical elements that carry such waves, such as wired or wireless links, optical links or the like, also may be considered as media bearing the software. As used herein, unless restricted to non-transitory, tangible “storage” media, terms such as computer or machine “readable medium” refer to any medium that participates in providing instructions to a processor for execution.

Hence, a machine readable medium, such as computer-executable code, may take many forms, including but not limited to, a tangible storage medium, a carrier wave medium or physical transmission medium. Non-volatile storage media include, for example, optical or magnetic disks, such as any of the storage devices in any computer(s) or the like, such as may be used to implement the databases, etc. shown in the drawings. Volatile storage media include dynamic memory, such as main memory of such a computer platform. Tangible transmission media include coaxial cables; copper wire and fiber optics, including the wires that comprise a bus within a computer system. Carrier-wave transmission media may take the form of electric or electromagnetic signals, or acoustic or light waves such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer-readable media therefore include for example: a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD or DVD-ROM, any other optical medium, punch cards paper tape, any other physical storage medium with patterns of holes, a RAM, a ROM, a PROM and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave transporting data or instructions, cables or links transporting such a carrier wave, or any other medium from which a computer may read programming code and/or data. Many of these forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to a processor for execution.

The computer system 1601 can include or be in communication with an electronic display 1635 that comprises a user interface (UI) 1640 for providing, for example, the one or more images of the cell that is transported through the channel of the cell sorting system. In some cases, the computer system 1601 can be configured to provide a live feedback of the images. Examples of UI's include, without limitation, a graphical user interface (GUI) and web-based user interface.

Methods and systems of the present disclosure can be implemented by way of one or more algorithms. An algorithm can be implemented by way of software upon execution by the central processing unit 1605. The algorithm can be, for example, a deep learning algorithm to enable sorting of the cell.

EXAMPLES

The following specific examples are illustrative and non-limiting. The examples described herein reference and provide non-limiting support to the various embodiments described in the preceding sections.

Example 1. Non-Invasive Prenatal Testing

Sample Preparation: Five to ten mL of maternal peripheral blood will be collected into an ethylene diamine tetraacetic acid (EDTA)-containing tube and a plain tube. For women undergoing amniocentesis, maternal blood will be collected prior to the procedure. Maternal blood samples will be processed between 1 to 3 hours following venesection. Blood samples will be centrifuged at 3000 g and plasma and serum will be carefully removed from the EDTA-containing and plain tubes, respectively, and transferred into plain polypropylene tubes. The plasma or serum samples must remain undisturbed when the buffy coat or the blood clot are removed. Following removal of the plasma samples, the red cell pellet and buffy coat will be saved for processing in the system of the present disclosure.

Sample Testing: Cells from maternal serum or plasma acquired from a pregnant female subject may be imaged using the system and methods of the present disclosure, wherein the cells are not labelled and placed in a flow. The cells will be imaged from different angles. In some aspects, said cells will be housed in a flow channel within the system of the present disclosure, wherein the flow channel has walls formed to space the plurality of cells within a single streamline. In some aspects, said cells will be housed in a flow channel within the system of the present disclosure, wherein the flow channel has walls formed to rotate the plurality of said cells within a single streamline.

While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. It is not intended that the invention be limited by the specific examples provided within the specification. While the invention has been described with reference to the aforementioned specification, the descriptions and illustrations of the embodiments herein are not meant to be construed in a limiting sense. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Furthermore, it shall be understood that all aspects of the invention are not limited to the specific depictions, configurations or relative proportions set forth herein which depend upon a variety of conditions and variables. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is therefore contemplated that the invention shall also cover any such alternatives, modifications, variations or equivalents. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby. 

1.-15. (canceled)
 16. A method for cell sorting, comprising: (a) transporting a cell suspended in a fluid through a flow channel, wherein the flow channel is in fluid communication with a plurality of sub-channels; (b) capturing one or more images of the cell from one or more angles as the cell is transported through the flow channel; (c) analyzing, by a deep learning algorithm, the one or more images of the cell to classify the cell; and (d) sorting the cell to a selected sub-channel of the plurality of sub-channels based on classification of the cell in (c).
 17. The method of claim 16, further comprising rotating the cell as the cell is being transported through the flow channel.
 18. The method of claim 16, further comprising focusing the cell into a streamline at a height within the flow channel as the cell is being transported through the flow channel.
 19. The method of claim 16, wherein the one or more images are captured at a rate of about 10 frames per second to about 500,000 frames per second.
 20. The method of claim 16, wherein the one or more angles comprise a plurality of angles that extend around the cell or over a portion of the cell.
 21. The method of claim 16, wherein capturing the one or more images of the cell comprises capturing a plurality of images from (1) a top side of the cell, (2) a bottom side of the cell, (3) a front side of the cell, (4) a rear side of the cell, (5) a left side of the cell, or (6) a right side of the cell.
 22. (canceled)
 23. (canceled)
 24. The method of claim 16, wherein the plurality of sub-channels excluding the selected sub-channel are closed using pressure, an electric field, a magnetic field, or a combination thereof while the cell is being directed to the selected sub-channel.
 25. The method of claim 16, further comprising validating the sorting of the cell using a light.
 26. The method of claim 16, further comprising sorting a plurality of cells at a rate of at least 10 cells per second, wherein the plurality of cells comprises the cell.
 27. The method of claim 16, further comprising: sorting a plurality of cells including the cell using a classifier; and feeding data from the sorting back to the classifier in order to train the classifier for future sorting.
 28. (canceled)
 29. The method of claim 27, wherein the classifier comprises a neural network that is configured to perform classification of each of the plurality of cells, based on classification probabilities corresponding to a plurality of analyzed images of the plurality of cells.
 30. The method of claim 16, wherein the cell is from a biological sample of a subject, and wherein the method further comprises determining a presence or an absence of a physiological condition or an attribute in the subject based on the analyzed image.
 31. The method of claim 16, wherein the capturing of the one or more images of the cell comprises illuminating the cell with a strobe light with an exposure time of less than 1 millisecond, wherein the strobe light comprises a wavelength selected from the group consisting of: 470 nanometer (nm), 530 nm, 625 nm, and 850 nm.
 32. The method of claim 17, further comprising applying a velocity gradient across the cell to rotate the cell.
 33. The method of claim 32, wherein the cell is flown in a first buffer at a first velocity, and wherein the applying the velocity gradient across the cell comprises co-flowing a second buffer at a second velocity.
 34. The method of claim 17, wherein an axis of the rotation of the cell and an additional axis of migration of the cell along the flow channel are different.
 35. The method of claim 34, wherein the axis of the rotation of the cell is perpendicular to the additional axis of the migration of the cell along the flow channel.
 36. The method of claim 18, wherein the focusing of the cell comprises subjecting the cell under an inertial lift force, wherein the inertial lift force is characterized by a Reynolds number of greater than
 1. 37. The method of claim 36, wherein the inertial lift force is characterized by a Reynolds number of at least
 20. 38. The method of claim 21, wherein capturing the one or more images of the cell comprises capturing a plurality of images from at least two sides selected from the group consisting of: (1) a top side of the cell, (2) a bottom side of the cell, (3) a front side of the cell, (4) a rear side of the cell, (5) a left side of the cell, and (6) a right side of the cell.
 39. The method of claim 16, wherein the sorting comprises (i) directing a first cell to a first sub-channel of the plurality of sub-channels and (ii) directing a second cell to a second sub-channel of the plurality of sub-channels, wherein the first cell and the second cell have or are suspected of having one or more different features.
 40. The method of claim 25, wherein the validating comprises determining information associated with the cell using blockage or scattering of the light.
 41. The method of claim 40, wherein the information associated with the cell comprises a size, shape, density, texture, or speed of the cell.
 42. The method of claim 25, wherein the validating comprises (i) providing at least two light spots on the selected sub-channel by directing at least two lights towards the selected sub-channel, and (ii) determining a travel time of the cell between the at least two light sports, wherein the at least two light spots are spaced apart by about 10 micrometer to about 1,000 micrometer.
 43. The method of claim 25, wherein the light comprises a laser.
 44. The method of claim 30, wherein the biological sample of the subject is selected from the group consisting of: blood, plasma, serum, urine, perilymph fluid, feces, saliva, semen, amniotic fluid, cerebrospinal fluid, bile, sweat, tears, sputum, synovial fluid, vomit, bone, heart, thymus, artery, blood vessel, lung, muscle, stomach, intestine, liver, pancreas, spleen, kidney, gall bladder, thyroid gland, adrenal gland, mammary gland, ovary, prostate gland, testicle, skin, adipose, eye, brain, infected tissue, diseased tissue, malignant tissue, calcified tissue, and healthy tissue, and wherein the malignant tissue comprises tumor, sarcoma, leukemia, or a derivative thereof.
 45. (canceled)
 46. The method of claim 16, wherein the flow channel is in fluid communication with the plurality of sub-channels via a sorting junction, the method further comprising predicting an arrival time of the cell at the sorting junction.
 47. The method of claim 46, further comprising: adjusting a velocity of the cell or a subsequent cell through the flow channel based on the predicted arrival time of the cell, to thereby modify the arrival time of the cell or an arrival time of the subsequent cell at the sorting junction; and sorting the cell or the subsequent cell to the selected sub-channel of the plurality of sub-channels.
 48. The method of claim 30, wherein the biological sample comprises maternal blood or serum.
 49. The method of claim 48, further comprising identifying the cell as a nucleated red blood cell (RBC), wherein presence of the nucleated RBC is indicative of a fetal abnormal condition, which fetal abnormal condition comprising fetal aneuploidy. 